By Bob Goemans
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The 'LIVING' Marine Aquarium Manual

Basic and Advanced Husbandry for the 'Modern' Marine Aquarium

by Bob Goemans

Chapter 2. Miscellaneous Equipment

There are numerous forms of equipment with many fitting nicely into a category that denotes their purpose, such as those used for filtration, processing water in one fashion or another, or providing light. Nevertheless, there are some that don't fit, such as with those that need to be deemed 'miscellaneous.' And since the aquarium itself fits nicely into this category, lets begin this chapter with it, as it's the basis for all other equipment needs.

(Please keep in mind all underlined word(s) are linkable files - just click on them and be taken to its content/photo. Also, all shown photos are clickable, which often allows a larger file to be seen.)


Size and shape is probably the first issue to resolve, as the aquarium must be of sufficient size to suit the needs of its theme and blend with the area where it will be placed. Furthermore its depth, i.e., front to back, in most cases should not be more than its owner's arm length as servicing anything in the rear of the aquarium will be extremely difficult to reach and/or probably receive inadequate care. For beginners, smaller aquariums often called nano tanks are extremely popular because many come complete with all equipment to have an up and running system without additional equipment costs. And the quality of seawater in these smaller aquariums can easily be maintained with periodical water changes and/or are fine for displaying small species that would be difficult to maintain or get lost in large aquariums.

In the past, its been recommended the best size aquarium is the largest that can be afforded, whether for fish-only or reef aquariums. I use to say the same thing but with the present cost associated with reef aquariums and the environmental value of its animals, find this advice no longer correct for reef aquariums. First gain the experience and knowledge necessary before moving on to larger systems, especially reef systems. Better to make mistakes in a small reef system than getting chest pains when a large system goes putrid. Yet keep in mind that in fish-only environments, where many marine fish are quite territorial and where stocking levels are often higher than those in the reef aquarium, the larger aquarium still makes sense.

And then there are those that would say when something dies in a 20-gallon aquarium there's only 20-gallons of water to dilute the problem. But in a far larger aquarium there is much more water to dilute the problem, therefore bigger aquariums is 'always' better! Actually, in my opinion, we need to get away from this type thinking as it breeds carelessness. Whether fish or invertebrates the goal from the start must be to understand the requirements of the inhabitants in our little slice of the ocean. Then have the best possible environment for their survival whatever the size aquarium!

High show-type aquariums are fine for fish-only systems where light need only be sufficient enough to view them. Yet in reef aquariums the higher the aquarium the more intense the lighting has to be to adequately penetrate its depth. Therefore, low and deep, with deep meaning front to back are much better suited for reef aquariums. Yet keep in mind the chosen environmental goal, as some require certain dimensions to replicate. If the aquarium's width, height or depth will not allow for a nice looking finished project, then the whole effort is wasted. In some cases a custom-made aquarium may be worth the additional cost. Also, having the back outer panel covered with a black or blue PVC panel may help with accomplishing ones theme, as it provides an impression of depth.

As for surface area a low 20-gallon rectangular shaped aquarium for example would have a larger water surface than a tall 20-gallon hexagon shaped aquarium. This is important because carbon dioxide is naturally being exchanged for oxygen at the water's surface, aiding one's effort to maintain a healthier aquarium environment. The more surface area the more gas exchange, therefore an aspect to possibly keep in mind when planning the desired system!

As for aquarium shape, modern technology is allowing for some interesting designs with both glass and acrylic, such as 'L' or 'U' shaped tanks, those with 'bowed' fonts, or those with a various number of side panels, e.g., three, five and six sides. There's also a system called 'Zero-Edge' where the aquarium's water evenly overflows all its top edges and flows down its outside vertical surfaces to a 'gutter' that surrounds the outside aquarium base, where it then flows to a sump located below housed in its accompanying cabinet. It contains no center braces and all animals are completely visible from above and also through its side panels, yet 'very' slightly distorted side views due to the water flow over them. The water in the supplied sump is then processed and pumped back to the aquarium via adjustable direction outflows that pass through the bottom surface of the aquarium. Suspended lighting equipment that hangs from the ceiling above, provided by the aquarist, provides the needed light. Even though evaporation in these systems is quite high, especially when located in dry climates, their bulk water oxygenation is always at saturation levels, a real plus for its animals.

Generally, aquariums are made from glass or acrylic, and as noted above, come in a wide variety of sizes and styles/shapes, and are well suited for freshwater or marine use. Manufacturers of quality made units should provide a guarantee/warranty in writing.

Nevertheless, there are two 'basic' styles - higher show aquarium (Photo Credit: Living Color), and the low profile aquarium. The show aquarium has greater vertical height and is more suitable for a fish-only system or for a special theme project that requires height more than width or depth. Generally, the quality of light needed for a fish-only aquarium need only be good enough to view the natural colors of the fish. The opposite would be true if the hobbyist was maintaining photosynthetic invertebrates because the quality of the light would have to be much better to penetrate the greater depth in the taller aquarium. Show tanks also have less surface area, somewhat reducing gas exchange. Low profile aquariums are usually a better choice for most reef aquariums.


The common glass aquarium is constructed of either float or tempered glass held together with non-toxic silicone adhesive. Sometimes it is framed with plastic molding of some color or style to give it a decorative appearance. Depending upon size, some have upper center bracing panels to keep them from bowing. All glass companies have a specification book that relates to the pressures it can withstand, which relate directly to the length and height of the type of glass utilized. Tempered is about four times as strong as float glass. Keep in mind glass siliconed to acrylic, or the other way around, is a bad idea, as each has a different rate of expansion and the seal between them would not last very long. It's either an all glass or all acrylic aquarium using the proper cements for each. Newer design glass tanks can be had with curved fronts and rounded corners, adding beauty to the aquarium, yet some additional cost.

There is a new form of glass, usually called Starfire or Starphire depending upon its source. Its extremely clear as its lead free and has low iron content. It is, however, more expensive than regular glass, but its clarity is equal to that of acrylic aquariums. (The high quality custom made glass aquarium in the photo was made by Jeff Turner - Reef Aquaria Design Inc.)

The glass aquarium has disadvantages and advantages:


  • Glass aquariums are heavier than acrylic aquariums. This is especially true for those that use plate/float glass. Some manufacturers use tempered glass, therefore, it can deliver the same strength of plate glass, yet only be about a quarter of its thickness. This can greatly reduce the weight of a glass aquarium.
  • Regular glass has less clarity then acrylic.
  • Glass is easily broken.
  • Glass is more difficult to drill then acrylic.
  • Tempered glass cannot be drilled at all.
  • Repairs are time consuming.
  • Glass does not insulate as well as acrylic.
  • The clear silicone sealant used to cement the panels of glass together may discolor in time. Medicating a system with copper may also discolor the sealant.


  • Costs less then acrylic unless it's Starfire glass.
  • More scratch resistant then acrylic.
  • Easier to clean algae off their inside areas than acrylic aquariums.
  • Silicone cement is easier to work with than the special fast drying cements applied to acrylic aquariums.


The acrylic aquarium is extremely strong, lightweight, and crack resistant. It can be molded into various shapes and/or with curved corners. The acrylic aquarium has disadvantages and advantages:


  • More expensive than regular glass aquariums.
  • Scratches easily.
  • Requires care in removing algae on inside surfaces.
  • Have small top openings when compared to glass aquariums to prevent bowing of the front and rear panels because this is a more flexible material.
  • Their molded tops somewhat impair light penetration, as there is more material for light to penetrate when compared with the top of glass aquariums.
  • Coralline alga is more difficult to remove than from glass.


  • Light in weight when compared to glass aquariums.
  • Easy to drill.
  • Has greater clarity than regular glass.
  • Scratches may be buffed out, however, on inside surfaces water must be drained down to the scratched area while the process is taking place.

  • Maintains a more stable water temperature, as acrylic is a better insulator than glass.
  • Have seamless corners.
  • Many come with overflows already installed.

Price is a driving force; therefore examine each for their merits before making a choice. Since this is a long-term investment, maybe a few dollars more the first time around will really be the least expensive way to go in the long run.


Considering the weight of the empty aquarium, glass or acrylic, and the weight of the living rock and that of water, which weighs about 8.5 pounds (3.9 kg) per gallon, the final product will no doubt weigh more than originally thought! If the stand is not sturdy, it 'will' cost you dearly! A few more dollars spent here on quality material may well prevent a tragedy in the future! And because of its entire weight, one needs to take into consideration the structure of floor that it will be placed upon. Is it level, is it strong enough to safely hold the weight of the finished product, and if in an apartment type dwelling, do you have permission to install the aquarium and its stand, as some of these living establishments do not allow aquariums on anything but the first floor.

There should also be some thought given to the access and usable space in the interior of the stand. Some aquarium systems require sufficient space under them to house equipment of various kinds, such as a trickle filter or sump. Stand height should also be given some thought since aquarium viewing in the home will probably take place by those sitting in front of it. Stands too low or too high not only affect viewing, it also impacts system maintenance, as anything difficult to reach usually receives improper care. Color of the stand and/or type of wood, if a wooden stand is in the planning stage, should also have some forethought, as an oak stand where all home furniture is that of cheery, would look somewhat odd.

Stands are made with various materials.


Wood is by far the most common construction material. Since most aquariums evaporate water at a great pace, the humidity inside and around the stand will usually be very high. To prevent the wood from warping due to it absorbing moisture, it's a good idea to coat its surfaces with a water sealant, at least on its inside, including the top and bottom of any interior shelf. If a trickle filter/sump is used in the lower portion of the stand, there will be very high moisture content inside and around the stand. Keep in mind stands constructed of particleboard may become unreliable strength-wise due to this materials ability to greatly absorb moisture. There are various waterproofing compounds on the market and recommend contacting your local paint store for suggestions. Remember to do the shelf really good on both sides or it may bow. Check local shops for slightly used stands 'and/or' used aquariums!


Metal stands for marine aquariums have become less popular because of their need for constant maintenance. Saltwater splash on most metals will cause rust problems. When it comes time to repaint metal stands, the aquarium cannot simply be lifted off in most cases and moved to another room. And keep in mind that metal paints are often quite toxic and even if only its vapor gets into aquarium water, a wipeout may occur.

Other Materials

Occasionally, stands made of waterproof acrylic/plastic materials are available, often molded in various colorful and attractive shapes. These have appeared to be very sturdy, easy to keep clean and basically require no ongoing maintenance. Unfortunately most seemed to be quite expensive. I've also seen stands formed with concrete blocks that used materials such as thin sheets of Styrofoam on their top surfaces to help absorb pressures from a possibly uneven surface. In fact, a Styrofoam or rubber pad underlining for the aquarium base is a good idea on almost any type stand as it helps reduce/eliminate unevenness in the top surface of the stand. This eliminates those uneven spots from transmitting pressure to certain areas of the aquarium, preventing possible future leaks. Since price is a driving force you are the best judge as to what will fit your pocketbook and be aesthetically acceptable. Yet keep in mind the stand is in someway the foundation of your 'aquarium world!'

Leveling and Testing

Once you have the aquarium in place make sure everything is level before adding water. Do not rush this item! If the aquarium were not level, a full aquarium would develop uneven pressures on its inside surfaces and quite possibly lead to future leaks. Also, if the aquarium has an internal overflow area and the aquarium is not level, it will not draw water evenly. After placing the aquarium on the stand, preferably on a cushioning pad as mentioned above, add a few inches of water and check to see if it's really level. If not, drain and re-level until its 'really' level.

Even though better than 99% of new aquariums are water tight you should give some thought at this time about filling it with freshwater all the way up to the top. Then waiting 24 hours to leak check it before proceeding. It's better to find out now than later when there are animals in the aquarium.


Aquarists usually place the aquarium where it will be the most attractive. Yet, before it's filled with water there are some other considerations besides it being level that should be taken into account:

  • Will it be subjected to hot or cold drafts?
  • Is it too close to the radiator or fireplace?
  • Will it receive direct sunshine, thereby possibly raising water temperature too high?
  • Is there sufficient electrical outlets close-by?
  • Is it in a walkway?
  • Is there sufficient space behind the aquarium for optional equipment?

Wherever you place it, a little planning goes a long way.


Not all commercially made aquariums, whether used as the main aquarium or sump come exactly as needed to accomplish one's goals. Some need tweaking/modifications so water can be distributed properly, i.e., removed, processed, then returned as desired for one's planned environment. This more often than not requires holes to be drilled or partitions/bulkheads to be installed. In the main aquarium, these water exit areas are called 'overflows.' To alleviate the need of drilling drain holes, (especially in glass aquariums) you may want to consider hang-on-tank (HOT) overflows, such as those from CPR that will allow inside surface water to exit without drilling any holes.

When necessary, keep in mind the purpose of holes and/or partitions are to help direct water flow, as most aquariums need to take surface water from their inside and have it flow to an outside located sump and/or filtration equipment, then return to the aquarium. Most aquaria use 'overflows' that are a box shaped structure built into either the rear inside corner(s) or somewhere along the inner rear side of the aquarium. Corner units can be made with one piece of acrylic, or two or three pieces of material (forming a 90 degree or 'U' shaped' structure then attached to the side and rear panel or somewhat centrally located and cemented to the rear panel.

As for the number and position of overflows, system theme dictates that requirement, nevertheless aquariums wider than 6 feet (2 m) should have at least two, with each probably best located in the rear corners. In fact, I've always preferred more than one overflow because if one clogs, it's wet carpet time since rarely would two clog at the same time. Two centrally back located overflows, each a couple of feet apart may also suffice.

Most inside partitioned overflows enclose a hole drilled in the aquarium bottom, yet I've seen some having it somewhat higher up on the side or rear panel for the bulkhead fitting because of interferences with the structure of the stand the aquarium is resting upon. In such cases, a shortened 90-degree PVC fitting for placement of the standpipe is inserted into its bulkhead fitting. Generally, the bulkhead fitting is installed in the bottom and a length of pipe, usually PVC and called a 'standpipe,' is inserted and cemented directly into the bulkhead opening.

The height of this standpipe does not dictate the water level in the aquarium in this type of arrangement; it's the partition openings that do that. In fact, the standpipe is only a central water collection device within the partition. This pipe can have many holes drilled in it at various heights to allow better flow into it and reduce the noise of falling water within it. In fact, if noise is a problem, as with aquaria placed in bedrooms, checkout the Durso Standpipe™( or the Maggie Muffler (black item w/4 holes) ( for a noiseless standpipe. And to keep unwanted floating matter from clogging the standpipe and/or equipment below, the upper edges of the partitions should have numerous toothed/slotted edge openings. And it's the depth of these slots in the upper partition that dictates the level of the water column in the aquarium.

I've found most aquariums, of course depending upon size and flow rates, to have a water level about .5 inch (1.25 cm) above the 'bottom' edge of the partition slots when the system is operating. Therefore, if there is a power outage, the vessel/sump below receiving the outflow from the aquarium needs to have some excess capacity to prevent it from overflowing. As for slot width, I've used .25 inch on all aquariums larger than 50 gallons, and .125 on those smaller, and always preferred to have partitions with more slots than seemed to be needed because there was always something that came along, such of a piece of floating fish food (Nori) that was found blocking some of the slots! Better more than less and not having a flood.

Some hobbyists form small trays of eggcrate material covered with mechanical filter medium, such as filter fluff, and place them on the upper opening of the overflow standpipe to 'mechanically prefilter' the water that enters the sump below. This, in my opinion, is a bad idea as these type filters usually quickly clog and if not diligently monitored can cause the aquarium to overflow!

If the sight of interior vertical overflows would detract from the finished environment, then the hole(s) for exiting water can be drilled into the back or side panels of the aquarium slightly below the preferred surface level. Then a bulkhead fitting is installed in this hole with its rear side connected with hard or flex piping to the sump or equipment below. On its interior side, a 90-degree PVC fitting can be inserted, with the length of its top opening shortened as necessary to dictate water level in the aquarium. When this type arrangement is used, its upper opening should be wrapped/surrounded in some sort of slotted or course mesh or screening material that won't rust, with its openings just small enough to prevent organisms such as snails and shrimp, and even some small fish from using it as a pathway into the sump.

For those brave souls that want to drill their glass tanks, in fact, even an acrylic tank, the hole used for draining water should be slightly larger than what is thought adequate for the desired goal of removing water. It is far easier to add a reducer fitting to the standpipe itself or elsewhere in the flow leaving the aquarium than drilling another hole or enlarging the previous bulkhead opening! Once the placement of the hole is decided, which should not be too close to aquarium edges, take the bulkhead inner seal and place it so that its properly located and ink a circular line to indicate its central opening. Generally, drain holes should be about 1.5 inch (3.8 cm), with the water return hole somewhat smaller, possibly about 1 inch (2.5 cm). Then cross your fingers and drill the needed hole(s)! Keep in mind that it's best to use brand new hole saws, as even slightly worn bits create unnecessary heat, and in the case of acrylic, can actually melt the edges of the material causing burrs that if not smoothed can cause future leaks. And with glass aquariums, use glass for the partitions and a silicone cement that say's on its label it's usable for aquariums. On acrylic aquariums, use acrylic materials for the partitions and only an 'acrylic' cement as mentioned above.

Depending upon aquarium size and theme, overflow locations and types can vary widely and if necessary to do it yourself, recommend researching all possibilities before any holes are drilled. (Maybe it's better left to a professional!)


The word 'sump' became popular when trickle (wet/dry) filters became popular in the mid 80's. Its bottom component, called a sump, was where the trickling water from above in this type equipment collected and generally housed a return water pump and some forms of mechanical filtration. Even though trickle filters have lost some of their popularity, especially in reef aquariums because its effluent contains an undesirable amount of nitrate, the use of 'sumps' in one form or another has grown in popularity. This occurred because it's simply a convenient area to house other forms of equipment, usually under the aquarium or nearby, such as protein skimmers and return water pumps to mention just a few. And most important of course, holding the withdrawn water from the aquarium, where it is often filtered somehow before being returned to the aquarium.

I've also seen sumps that were plain 10 or 20 gallon glass aquariums, and those far more exotic that could hold various filtering aids costing much more than a simple common glass aquarium. Sump design has come a long way over the past decade or two! Therefore, depending upon your needs, I'm sure there is a ready made unit somewhere out there that will fit your needs.

As to their overall capacity, keep in mind if there is a power loss the water level in the aquarium will drain down to the lower edge of its internal openings, whether that be its vertical/side located bulkheads or partition slots, and all this water along with whatever water is in the piping will then flow into the sump. Therefore, be sure to have enough capacity to hold it or it will be wet carpet time!

Building a Plywood Aquarium

One of the nice things about building your own aquarium is that it can be shaped to fit almost any specific location. It can also be built for a fraction of what a readymade aquarium would cost. Since some people are quite handy with tools I'm including here a recipe for making a plywood aquarium. A fellow hobbyist and myself built a couple of plywood aquariums in his home over a decade ago. Both were very successful. What is noted below is a brief, somewhat now dated view of that process and materials used, but nevertheless, a somewhat good idea of what it takes.

Needed tools include a drill and various size drill bits, saber saw, screwdriver, and some paintbrushes. Materials included the best grade of marine plywood, tempered plate glass, brass screws, marine epoxy paint with hardener, a waterproof sealant that is designated for aquarium use, waterproof glue such as a polyurethane product (Gorilla Glue, Excel, Elmers, or TiteBond), and sandpaper.

To begin, you'll need a drawing of the tank with all its dimensions showing where the glass viewing piece(s) will be installed. Prepare a list of what size wood and glass pieces are needed. Keep in mind the glass goes on the inside and needs to overlap the plywood by at least 1 inch (2.5 cm) in all directions of the opening and not be located at less than 2 inches (5 cm) from the sides, bottom, end or top of the tank. It's preferable that a professional cuts the plywood panels, possibly the lumberyard where it's purchased. That way the corners of the material will be exactly square. The glass panels, possibly shaped as portholes, should be beveled on the side facing the interior of the tank. That way you'll not cut yourself when performing window cleaning and may also protect some of the inhabitants.

Purchase a very good grade of marine epoxy paint. It is sold in two parts and must be mixed when ready for use. I recommend two coats on the vertical panels and three coats on the bottom. Check stores that specialize in boat supplies or possibly a hardware store.

Brass screws are recommended because they will never rust, which is a comfortable feeling in the long run. Just keep in mind they are a fairly soft material and cannot be screwed directly into the wood as they may break. Because of that it's first necessary to drill pilot holes of a slightly less length and diameter of the screw. It's also probably better to use a manual screwdriver than an electric one, as screwheads may become damaged in the final tightening.

Once all the pieces are cut, place the bottom piece in an area where there is sufficient space to work. Locate the end pieces, which have a width slightly less than the bottom panel, inside the side pieces (front and back) and on top of the bottom piece. Note that the side pieces are the same length as the bottom piece. With a pencil mark the points where the screws will be inserted. These will be located 1 inch from the edge of each piece to be joined, then one more screw approximately every few inches. Large aquariums can have slightly more distance between them. Then remove each piece and drill and countersink the holes. Then reassemble the tank with the pieces loosely held together with the screws, yet with sufficient space between each piece to apply the glue.

If yellow-like wood glue is used, apply a lot of it and wipe away any excess that flows outside the joints. If polyurethane glue is used, first wet the joints with water as moisture helps set the glue. Follow the manufacturers instructions for applying the glue. Now tighten the screws, but don't over-tighten them. Work one side of the tank, then the opposite side. That way, an even amount of pressure is applied to the joints. Once assembled, remove any surplus glue on the joints.

Allow the tank to set-up and dry overnight. If the tank is over 6 feet in length its time to glue bracing strips (prevents the tank from bowing when full) into place. One strip every 2 feet should suffice. These should be 1 - 3 inch (2.5 - 7.5 cm) wide strips, possibly larger depending upon the size of the aquarium, that connect front and back panels. Place the strips even with the top edge and pre-drill the necessary holes and countersink. Loosely secure the braces with some screws and apply glue, then secure the screws.

If the tank will have a cover(s), prepare some short square strips and secure them (drill holes, countersink, and glue) a distance equal to the thickness of the cover material below the top edge of the tank. Keep in mind if the choice is a wood cover(s), they can have openings for lights to shine through. These openings could also be fitted with glass panels to lessen the transfer of heat. Holes for lifting, siphon tubes and other support equipment can be placed as needed. Space the support strips as needed so enough is used to support the covers.

After everything is completely dry, sand the joints and the edges (inside and out) of the opening where the glass panel will be placed. Apply two to three coats of the interior epoxy paint, including the covers per the manufacturers instructions. Sand lightly between coats. After the paint has dried thoroughly its time to seal the joints. Apply the sealant of your choice to all the joints and smooth as necessary. Then turn the tank so that the area receiving the glass panel is facing downward. Place a liberal amount of sealant around the opening and place the glass on top of the bead of sealant. Weight the glass panel down with a pail of water or something heavy enough to secure a good seal. Make sure to cover the glass surface with paper or cloth so it does not become scratched. Once dry, stand the tank up and carefully seal the front side of the panel making a nice smooth seal.

Once everything is dry it may be time to fill the tank and check it for any leaks. If any are found, dry and reseal. Filling the tank also helps to cure the paint used on its interior. Recheck as necessary. Empty and dry the tank and now apply three coats of a quality brand marine varnish to all outside portions, including its bottom. Let dry and then your ready for the final filling! Again, this all occurred well over a decade ago, so if something like this is of interest, do your homework before beginning.

Temperature Control

Almost all aquarists understand the need for temperature control, as too low or too high temps can cause negative animal health problems. Having lived in both frigid and sweltering portions of various countries, I know from past experience the need for precise temperature control in aquariums. And the more I had invested in my aquariums, the more I needed this aspect properly controlled. Therefore, most should be equipped with thermostatically controlled heaters and/or chillers. Ideally, most aquariums should stay within 77 – 80 ºF (25 - 27 ºC), and not incur more that a few degrees in overall up or down swings per day.


Most aquarium heaters are inexpensive and long lasting and there's several styles to choose from, e.g., substrate cable-like heaters, flow-thru models, those that attach to the side of the aquarium using suction cups or a supplied bracket, and mat-like units.

Those buried in the sandbed, i.e., cable heaters, such as those that are sometimes used in freshwater plant aquariums, if suitable for marine aquariums, can provide adequate bulk water heating without it distracting from overall aquarium appearance. Nevertheless, should it become inoperable at sometime in the future, its removal in an established aquarium is impossible without disturbing a good portion of the environment and its inhabitants. It would simply be better to leave the buried inoperable cable heater in place and install another type heater somewhat in the system.

Hydor has some innovative designs, such as their ETH In-line heater, which can be placed into the return line from a canister filter, or their EKIP heater, which has a small internal pump that pushes water through its heating element, providing both heat and additional water movement. There are also small mat-like heaters that provide a fixed temperature; however, because of their size are only effective in small aquaria, e.g., below 3 gallons. And other improvements, e.g., shatterproof enclosures, electronic circuits, and auto-off capability should water level fall and the unit becomes too warm, are now seen in many different brands and model types.

As for heater size, a rule-of-thumb is 3 to 5 watts per gallon. Keep in mind should a heater malfunction and stay on, it will take longer to overheat an aquarium with a lower wattage heater than one of higher wattage. In cold areas where a higher wattage heater would prevent large swings in temperature, recommend using two or more smaller wattage heaters, depending upon aquarium volume, than a single high wattage heater.

Placement should be in an area where there is sufficient water movement. Insufficient water movement past a heater can cause a high heat area near the heater, possibly stressing any animal that comes too close. Sump areas where there are no snails and other slow moving animals may be the best place to locate a heater. Also, during water changes, aquarium water level may drop exposing a portion of the heater element tube. This may cause the protective glass tube in some models to overheat and break creating an electrical hazard to both the aquarist and the animals in the aquarium. Give some thought to disconnecting heaters during water changes.

Select heaters that have a clear simple temperature gauge, something easy to adjust, an easily seen on/off light to indicate when it's operating, and is rated as totally waterproof. When installing a new heater allow for the unit's internal temperature to match the temperature of the aquarium water before plugging it in and setting its temperature. This may take about an hour or two to accomplish. Locate where there is a constant water flow so as to provide a more even temperature in the aquarium. If using a heater cable in the substrate, set it about one degree higher than the desired temperature for the system's bulk water, as sand is a somewhat insulating material. Depending upon aquarium inhabitants a protection device may need to surround the heater tube or the heater itself may need to be partitioned-off from the rest of the aquarium. Stay with well-known name brands.


Since I reside in southern Arizona, the heat factor is more troublesome than the cold factor. In fact, when we moved here many years ago we found that summer daytime temps could and did reach 117 degrees! It was economically impossible to air-condition the entire home and maintain it low enough to keep my aquarium within its proper temperature range when the lighting system was lit for more than an hour or two! I did try low home temps, but it got to the point where I was afraid to look at the electric bill when it arrived! And in those days, the early nineties, a chiller was more something for a store that sold lobsters for human consumption. Yet I did try one of the first hobbyist Baytech models, but it had its problems!

But with powerheads, system pumps, metal halides and fluorescents adding heat to the many systems I've kept over the past 20 years; chillers became a necessary equipment item. And warmer climates also added to excess heat problems! And the same is true for my local clients who have aquariums ranging in size up to 600 gallons. Therefore, there is at times a need for a piece of equipment made especially for cooling marine aquariums! These devices, actually small fan-cooled industrial refrigerators, usually have a heat dispensing grid of titanium evaporator coils, a compressor, and a motor. In the years past, chillers were bulky, but modern units are slim and easily placed in convenient areas.

Some new models have computerized LCD touch-sensitive screens, e.g., TECO SeaChill, where simply touching it can set temperature settings in Fahrenheit or Centigrade. Look for features such as:

  • Automatic resetting to the selected temperature setting should there be a power failure.
  • Have an easy to remove and clean dust screen that keeps dust from building up on the interior chiller plumbing, which can cause the unit to work harder and longer to maintain the selected temperature. And possibly have a program built-in to flash a warning light indicating that its time to clean the dust screen!
  • May come with a heater installed that automatically functions when water flowing through the unit falls to about 1.5 degrees below the cooling set point, thereby maintaining a very steady overall temperature in the aquarium.
  • Possibly a build-in UV sterilizer.
  • Integrated diagnostic software.
  • Fast connect and disconnect valves for 'canister' filter-like hook-up.
  • Electrical surge protection/UL listed.
  • At least a two-year warranty.

The only routine maintenance chillers need is the occasional cleaning of the dust that collects on its internal condenser fins and coils. In the past, I had to unbolt the cover of my units to accomplish this dust removal, which was usually once or twice a year. Quite annoying to say the least, but necessary! Now, some brands have an easy to remove dust filter, and this is a great time saver, both for you and the chiller! Also worth mentioning is that all chillers should be mounted so their air exhaust is vented to outside the home air. If mounted in a cabinet under the aquarium the hot air exiting the condenser fins will build up under the aquarium. When that surrounding air becomes very warm the unit fails to properly cool the gas/liquid passing through it and has to work longer to accomplish the needed temperature drop. If the unit's hot air cannot be vented outside, at least point a small fan towards the air inlet side of the unit, which will help shorten the run timeframes.

As for size, an undersized unit will have to run far longer to accomplish its task then if it were slightly oversized for the aquarium for which it was purchased! Therefore, when it comes to the cost of electricity, it is wise to purchase a unit that is slightly oversized. Note I said 'slightly,' as units significantly oversized are not recommended as they cycle on and off too frequently, called 'short cycling,' and not only wastes electricity as most is used to start the unit, it also puts more wear on the unit, as it is also more significant during start-up. When it comes to picking a chiller, they are rated in Horse Power (HP), e.g., 1/6, 1/5, 1/4, etc., with each manufacturer having chiller sizing charts that should be reviewed before their brand is selected.

Furthermore, these charts are somewhat standard in the industry; therefore they should be considered just that, as they do not relate to the actual conditions that encompass 'your' aquarium. Your aquarium may contain species that require exact temperature control, may be placed in a poorly ventilated room, may be placed in a room experiencing wide changes in temperature, may have high intensity lighting/other heat generating equipment, etc. Purchase a chiller with these situations in mind, then go one size up, i.e., if a 1/6 HP unit would seem to be adequate, select the 1/5 HP unit, which is one size larger.

Aquarium "chillers" come in two types: flow-through or remote probe models.

Flow Through

The flow through model requires the hobbyist to plumb the unit so aquarium water will flow to and through the unit before returning to the aquarium. Manufacturers will recommend a given water flow through their units, and often recommend a size and possibly a brand water pump to accomplish that need. The hobbyist will then have to purchase and install a pump that will deliver the recommended flow, and most units today hook-up with no more effort than what it takes to connect a canister filter.

But on very large aquariums using much larger chillers, there are situations where hard piping, usually PVC, and various fittings are needed besides a dedicated pump. In such systems its necessary to design the physical layout of the piping correctly so air will not become trapped in any portion of the piping system. An air pocket could diminish water flow through the chiller and may result in a failed compressor. In fact, most aquarists fail to measure the outflow to see if it falls within the manufacturer's specifications for outflow per the chiller model being used. Keep in mind that turns and bends in chiller system piping reduce water flow and each piping angle may reduce water flow by three to five percent. The chiller outflow pipe should have insulating foam placed over it also to help conserve energy.

As to other considerations for this type hookup, pump quality/size is an important factor. How high does it have to lift the water to be chilled to get it to the inlet of the chiller? This is referred to as 'head' pressure and some aquarium pumps can deliver water several feet high without a reduction in flow. Some pumps experience severe flow reduction after just pushing water a few inches in height. Research pump selection carefully! And as noted above, could there be a high point in the chiller piping that may be collecting air/reducing flow rate. Double check piping layout! Another possible consideration to give some thought to is the chiller system being provided with filtered water so nothing will clog its piping system? These are all situations that need to be addressed when hard-plumbing a chiller system.

Remote Probe

Remote probe chillers need no external plumbing and for all practical purposes are 'plug in and use' type equipment. Yet, they do require good water flow past their probe when operating. When their remote temperature sensor turns the chiller on, its compressor directs a high pressure/high temperature gas through the condenser where it is turned into a liquid. The liquid then proceeds through a nozzle(s) where it expands very rapidly causing it to become extremely cold as it changes to a low-pressure gas/liquid as it flows through an evaporator device, i.e., the remote cooling probe.

Should not enough water flow past the remote probe when the chiller is operating, not 'all' liquid will be converted to gas. Should this condition go unchecked, its overall cooling will be greatly reduced, causing the unit to run much longer. I've used these type units in the past where the chiller itself was located next to the aquarium, with its probe located in the sump under the aquarium where a submerged powerhead supplied ample water movement over it. These are what I call truly plug and play equipment! Really simple to use and maintain and they come in different sizes.

Nano Cooling

Cooling, as in most large systems, require a standalone chiller to keep system temperature in the proper operating range. Besides somewhat costly, they take up a lot of additional space along with involved plumbing connections in some cases. But if one were going to have a nano tank, I would think having something almost as large as the aquarium next to it for cooling would be distracting to say the least. But previous research with CoolWorks Inc., now called Nova Tec Products, showed that they had a product called the 'IceProbe' that could be used in a modified hang-on-tank (HOT) filter!

IceProbe is a small thermoelectric chiller about 4 inches (10 cm) square, having a 1.5 inch (3.5 cm) high main body with a muffin fan attached to its top surface and a cooling probe extending 3 inches (7.5 cm) from its lower body. Overall height of the unit is about 7 inches (17.5 cm). The upper portion of the 'probe' is threaded and contains a nylon nut and silicon washer so it can be mounted as you would any bulkhead fitting. If mounting it through the wall of an aquarium or sump, an approximate 1.25 inch (3 cm) hole is needed to accommodate the probe.

Since I didn't want this unit sticking through the side of my small tank, I decided to locate the device in a Hagen AquaClear Power Filter. By cutting a hole in the filters cover plate, removing its filter media holder and filter medium, the IceProbe's probe fits through the cover and into the empty filter medium space with its probe sitting in the water returning to the aquarium. This then provided additional water movement and temperature control. Along with its automatic Proportional Thermoelectric Controller (has a temperature range of 65 to 85 degrees) and its 12 VDC Power Station it was the ideal way to control water temperature, and was set for about 79 degrees. During winter months when cooling is not needed, the IceProbe and the HOT filter is removed and stored until the following warm season.

This has proved to be an 'ideal' way to resolve both heating and cooling parameters, as the tanks heater comes on at about 77 degrees, with the system not getting any cooler than 76, nor warmer than 80 degrees. Ideal for small aquariums, with each IceProbe effectively said to cool about 10 - 12 gallons of water, however it seems to effectively control water temperature in my 30-gallon nano aquarium!

There are also small, reasonably priced chillers designed especially for nano aquariums, and their size makes them ideal for placement inside the smaller cabinets/stands that hold these smaller aquariums. Check them out on the Internet.

Evaporation Coolers

As mentioned above, I live in southern Arizona where summer temperatures get quite warm, - but many of the locals say it's not really too bad, as 'it's a dry heat.' True in some ways, as summer humidity is almost always below 10% with the dew point sometimes in the negative range. To save energy during these months most homes in this area turn to what are called 'swamp coolers' where water trickles downward over a large porous pad of material where air is pulled inward through it, evaporating the water quickly and thereby reducing its temperature significantly. In fact, we can have 110°F outside, and experienced a cool 72 degrees inside our home when the 'swamp cooler' is operating. But when outside air moisture greatly rises, e.g. above 40%, which is during our latter summer monsoon period, these coolers no longer work efficiently, and we have to turn to air-conditioning to remain comfortable.

This is mentioned here because the Deltec GMBH Company ( is selling a similar, yet smaller devices for cooling aquariums. It uses the double layer spiral black Enkamat and white polyester material that was used in trickle filters until bioballs became more popular for dividing and slowing the water flow in the area where outside air is drawn inward. Its far less expensive than a chiller and requires much less electricity, but might deliver less cooling than required, especially if located in a high humidity area/locale. Check it out by visiting their website.

Supplemental Cooling

There are a few hobbyists that have found the cost of chillers prohibitive and/or only needing some minor cooling during certain seasonal timeframes. Some have simply turned to lowering the home thermostat and increasing the use of their home or room air-conditioner. Others have turned to more inventive ways. There is the story of one using a small refrigerator and simply placing the aquarium's canister filter inside it. He then placed a wooden block the thickness of its tubing in the door opening and used duct tape to close off the remaining door opening where the electrical cord and water tubing entered and exited. The plug for the refrigerator and canister filter were both on the same on/off switch, and according to the user, it worked well for his seasonal needs.

Another told of placing an air pump inside a small refrigerator with its air going to an airstone in the sump and/or supplying cooled air to a small skimmer. He blocked all of the remaining open door space where the electrical cord, airline tubing, and a small diameter piece of plastic pipe for air intake was located. He said it worked well for his purpose, but I had to question condensation and ice buildup possibilities inside the refrigerator, but I never received a return reply. Nevertheless, both of the above ideas are most interesting to say the least.

Placing ice cubes inside a plastic bag, sealing it and then floating it in the aquarium or better the sump, is a short-term solution that can also possibly help get past a few exceptionally hot days.


Since fish and invertebrate are cold blooded, the temperature of their environment affects their activity, e.g., feeding, immune system, and other metabolic functions. Too low temperatures slow the animal's activity, which reduces uptake of vitamins and minerals and may result in reduced growth rate, disease, or death. Higher than normal temperature ranges actually result in a greater than normal need for food, which in turn generates more waste, and may lead to a higher system pollution level. Therefore, having an accurate thermometer, maybe more than one in a large aquarium is absolute necessarily.

Some of the floating, hang-on-the-side, and/or weighted thermometers may still contain liquid mercury, and if accidentally broken will release highly toxic mercury into the aquarium water and poison all its animals. In fact, what can be in a common thermometer, about one gram, is enough to contaminate a 20-acre lake. Countries such as Sweden phased out mercury thermometers in 1992. Some US state governments are also banning mercury, e.g., Michigan has banned mercury in schools; the city of San Francisco and the State of Minnesota has banned the sale of mercury thermometers. Other states and cities are also considering banning sale of mercury thermometers. However, some have now changed to other types of fluid, therefore, if no sure of its liquid content, contact the maker for details.

Liquid crystal types are thin strips of plastic material filled with temperature sensitive liquid crystals. This internal medium is temperature dependent and its physical expansion or contraction matches appropriate digital markings on the strips outer surface. This type of thermometer has an adhesive backing and is attached to the outside surface of the aquarium. Its internal liquid crystals are activated by the heat conducted through the aquarium panel and are highly accurate. (Photo Credit: TAAM)

There's also an array of battery powered digital read-out thermometers available and they are economically priced and very easy to read, besides being much safer than the old fashion thermometers containing toxic mercury. PinPoint has a wireless thermometer that can send its sensor reading to a LCD digital readout monitor up to 100 feet away. (Photo Credit: Craig Smith) Others, such as the digital Time or Temp have a reading that can display either the present time or temperature from its remotely connected probe. Handheld units that quickly and very accurately respond when their tip is submerged in water are also available. There's also infrared models where you simply point the device at the target, such as the water in the aquarium, pull its trigger, and its temperature becomes visible in its small window.

Keep in mind its better to place the model's sensor at least a few inches (7.5 cm) below the water surface if feasible, as readings closer to surface water may be somewhat affected by the temperature of the air or heat from intense lighting at its surface. Furthermore, in large aquariums, having a thermometer in several places in the system may provide information on the adequacy of water circulation within the system. There are many choices, and all have a variance of accuracy, e.g., 1 - 4 degrees, so stay with proven brands, maybe with digital models the best.

Dosing Equipment

Aquarium water evaporation is an on-going occurrence, making its replenishment a time-consuming and daily task for some hobbyists. Keep in mind too much evaporation without adequate replenishment will increase salinity levels and may result in stressed aquarium inhabitants. And the not thinking aquarist could compound that stress by adding too much makeup water at one time. Fortunately, aquarium product companies have produced a wide array of what are termed 'dosing equipment.' These devices are used to slowly makeup for evaporation throughout the day, with some also capable of dispensing liquid additives of various kinds.

Having equipment that will automatically meter adjustable amounts of water into the aquarium/sump reduces daily maintenance and produces a more stable environment. Some dosers can be set to provide constant drip rates, others will dispense various amounts at pre-determined times during the day. Some come fully equipped, but some may require a separate air pump, timer, and/or water pump. All of course require a container of some size determined by the aquarist to hold the make-up water.

Some units are quite simple such as the Kent Marine AquaDose units that work via gravity with its drip rate controlled by a IV/clamp. More advanced units, such as the LiterMeter from SpectraPure are on the high-end of the scale when it comes to dosing equipment. With my schedules, my aquariums would not survive without dosing equipment. Since there are many different brands on the market, the best way to judge what fits your needs is possibly to answer some of the questions below and then look for a brand/model that will accomplish those needs:

  • Is its pump noisy?
  • Does it come with all necessary fittings?
  • Can the flow rates be easily varied?
  • How much flow can it handle on a periodical basis?
  • Can it be easily disassembled for maintenance/does it need periodical maintenance?
  • Can it handle corrosive fluids such as Kalkwasser?
  • Can it temporarily operate dry without burning out its pump/motor?
  • Does it have a reasonable warranty?

All those factors and more may pertain to your need, however, simplicity and precise control of the water level and the pump strength to get it to where its needed is paramount.

Water Pumps/Powerheads

Every system needs dependable water pumps, as water movement, whether through the aquarium itself or associated equipment is paramount to the success of the overall aquarium system. For aquarium use there are generally two types, submergible and cooled by the surrounding water, and non-submersible pumps cooled by surrounding air. They are most often rated in gallons per hour (GPH) or liters per hour (LPH).

Almost all very large pumps used by public aquaria and aquaculture companies are direct-drive units. With these, the impeller sets on one end of the motor shaft and is located inside a chamber receiving water through an inlet connection. There is a watertight seal around the shaft to prevent water from coming in contact with its motor. As the shaft/impeller rotates, usually at high speeds, water is forced out through its outlet connection. Some of the generated heat from these air-cooled pumps is transmitted through its shaft to the water flowing past its impeller; therefore their used in anything but large commercial enterprises is often quite limited.

So why bring this form of pump to your attention since 99.9% of all hobbyists do not use this type pump? Good question, and the reason is there have been some aquarists that have used this style 'Jacuzzi' or swimming pool pump for their aquariums saying the impeller is saltwater safe, and their higher HP ratings are ideal for their large complex systems. Upon further investigation into these pumps it was found some of them use impellers made of bronze, which is a combination of copper and tin, or brass, which is a combination of copper and zinc. Eventually, erosion and/or oxidation may lead to copper entering the water, which is a death sentence both fish and invertebrates, as they are highly sensitive to this element. Also their seals have limited life spans, and will leak sooner or later depending upon the quality of the unit. Therefore, before going this direction, find out the makeup of its impeller and how much heat the motor transmits to the water flowing past it.

Where the general hobby is concerned, most stand-alone pumps are magnetic drive models where their impeller/rotating vanes are housed in a separate chamber where magnetic forces are used to transfer rotational drive from the motor through a waterproof wall. Therefore the motor shaft doesn't need a seal to keep water from contacting it. They come in two forms, submergible, usually called powerheads, and non-submergible pumps.

The non-submergible, air cooled pumps are sometimes used on aquariums where large volumes of water need to be moved, such as where its outflow is sometimes also used to power other forms of equipment, e.g., a protein skimmer besides general water movement in the aquarium. In these cases, it's usually called a 'system' pump, and a good yardstick for their selection is that their GPH should be four times the volume of the aquarium, not counting the needs of additional equipment if so equipped, which should be added to this number.

Some manufacturers, e.g., Little Giant and Iwaki, produce two types of non-submergible system pumps; one for circulation where there is little backpressure, and one designed specifically to handle greater backpressure. An Iwaki RLT model will deliver less water than a RLXT model, but deliver it to a wider range in head pressure. If water does not have to be raised too high, circulation models, i.e., 'X' models, move greater volumes of water at lower heights. Therefore, when you choose a system pump, make sure to select the model that best suits your needs.

Not only are these pumps leak proof, a small pebble caught in the impeller housing, which can happen sometimes, will only dislodge the magnetic force causing the impeller to stop rotating. Therefore the motor shaft can continue to rotate, preventing overheating. Simply stop the motor, open the chamber with the impeller, remove the obstruction, retighten the fittings and restart the motor. Yet keep in mind there should be a shut-off valve placed in the piping coming to that impeller chamber and one in the piping leading away from this chamber. That way, if located very close to the impeller chamber, they can shut-off water flow in both directions while the maintenance is being performed with little loss of system water. Also, locating these magnetic driven air-cooled pumps in well-ventilated areas helps keep their operating temperatures somewhat lower, nevertheless most aquarists seem to place them in an enclosed area under the aquarium cabinet. If so, think about using a small wattage fan to blow cooling air over this type unit, as I've found this helping to limit heat transferred to the aquarium and surrounding areas.

Keep in mind when selecting a system pump the two most important parameters are maximum flow rate and the maximum backpressure the pump can overcome. Maximum flow is the amount of water the pump can move with no resistance. It is usually measured in height and is generally characterized graphically on the accompanying pump literature showing its relationship to maximum backpressure.

Maximum backpressure is generally referred to as 'Head' and is the amount of resistance the pump can overcome and still continue to deliver water, and is usually measured in one-foot increments. As water moves through pipes and fittings and upward against gravity a resistance or backpressure is created. When resistance equals the ability of the pump to move water upwards, no further water is delivered. At some point, regardless of design, the performance of all centrifugal pumps declines with increased head.

Vibration is another area of attention that needs some forethought. Low frequency sound waves from a motor can be transferred to the aquarium stand and tank. Therefore, non-submersible magnetic drive pumps are better mounted on an insulated wooden base. They are also better if connected with flexible vinyl tubing instead of ridged PVC tubing that in turn could transmit any vibration throughout the system.

When selecting a pump, especially a system pump, keep in mind the higher the water is raised, the less flow. Also take into consideration the number of turns in the distribution piping. The longer it is and the more fittings, the more resistance to flow. One straight-line fitting may reduce water flow by one percent, an angle by five percent and every 10 feet of pipe by an additional five to ten percent. Therefore a pump rated to deliver 400 gallons at 4 feet of head may only deliver 200 gallons at 4 feet in a complex distribution system. It is always better to have a larger system pump than needed as excessive water movement can always be controlled with a gate valve placed in the outflow piping, but nothing can be done about insufficient water flow. And 'throttling' of the flow will not harm its motor. Also, it also pays to keep a spare pump in reserve!

Another factor to consider when planning the aquarium is the location of the system pump. If located above the aquarium, a self-priming pump is the best choice because if there is a power outage, when it restarts it will pull water from below it and push it to the aquarium. If it were a non-self-priming pump, which most system pumps are, it would if located above the water, lose its water supply and when power came back on, run dry and possibly overheat. Therefore, non-self-priming system pumps should be located below or next to the source of water it is sending to the aquarium.

Powerheads are submergible magnetic driven pumps and greatly vary in size, both physical and GPH, and efficiency. In fact some are large enough to be used as system pumps and can be located directly in sumps. In fact, some brand powerheads, e.g., SEN models, can either be submerged or externally mounted and plumbed to a water supply, reducing heat transfer to surrounding water if submerged.

These type powerhead units usually have a coil imbedded in epoxy that generates a field around the impeller magnet, causing it to rotate. Some come equipped with a venturi allowing for aeration of the water being pumped. Most of these type pumps provide 'additional' aquarium water movement, and are especially useful when the system pump is undersized, or additional water movement is needed because bioload has increased. Keep in mind it's the surrounding water that cools some of these submergible units; therefore, some heat is transmitted to the bulk water.

Some newer versions have their motor located outside the aquarium side panel with the impeller housing magnetically held directly across from them on the inside. Even though their motors are air cooled and outside the aquarium, some heat is transmitted to aquarium panel, yet far less than if it were a totally submerged unit. Furthermore, besides having its electrical cord outside the aquarium and being able to place it where convenient and remove it easily if it needs service, some are now coming with adjustable flow rates, e.g., the VorTech that has an adjustable flow rate between 100 - 3000 GPH and/or wirelessly controlled models! Consider placing these type pumps on timers or controllers for on/off performance that can mimic tidal flows or act as wavemakers and they become even more useful.


There are electronic switching devices that allow water flow from remote located water pumps, usually powerheads, to be alternated so as to simulate surge and flow of tidal currents in the aquarium. Also available is the non-electric SCWD (Switching Current Water Director) that uses water pressure from a user supplied pump to alternate current flows from the device. Keep in mind that water movement around coral and anemones is extremely important, as it not only carries away their waste products, it also brings food and dissolved gasses to them, e.g., oxygen and carbon dioxide. Simulating water flow as is in nature, i.e., back and forth wave motions helps provide a more healthy environment than one direction water flow since it exposes more animal surfaces to light and current flow.

Quality electronic wavemakers should be equipped with 3 prong outlets and allow for a wide range of pump on-off time frames. Having LED operating lights is a nice feature so as to indicate which pump is operating. Some wavemakers allow for complete shutdown of all pumps for feeding with a push button/switch, and/or have a sensing element that automatically reduces flow rates at nighttime. Be cautious when hooking up pumps, as their starting electrical current draw will typically be higher than what is stated on the unit's data plate, therefore do not overload the wavemaker's recommended amperage limit.

Wavemakers are probably not needed for many fish-only systems, yet are highly recommended for reef aquariums. In fact, the wavemaker is probably the most over looked piece of equipment for the reef aquarium and their benefits may not truly be realized until after they have been used for a while. They can be extremely high quality units, or simply low cost powerheads plugged into a 24 hour light timer with different on-off timeframes.

Air Pumps

There are probably not many hobbyists that have never used an air pump for increasing gas exchange, providing additional current, or aiding filtration. But for those that have not, there are several categories of air pumps, e.g., rotary air blowers, piston pumps, and the most common and most popular the diaphragm/vibrator type.

Rotary air blowers provide the greatest volume of air and can service many tanks simultaneously, yet are noisy and consume a lot of electricity. They are basically used in breeding or holding facilities where there is a wide need for a huge air supply and where noise is of little concern.

Piston pumps were popular a decade ago where noise and underachieving vibrator pumps did not meet the need. They are still available in one or two cylinder models and meet the needs in some applications, such as in pond use. For systems requiring large amounts of air, piston pumps can generate 20 pounds or more, however they are far from quiet!

For general aquarium use diaphragm/vibrator have superceded air blowers and piston pumps. They are fairly quiet, consume little energy, are relatively inexpensive, easy to service and usually rated at 2 - 4 Pounds per Square Inch (PSI), with some exceeding 7 PSI. Maintenance involves checking/replacing worn diaphragms, flapper valves and/or air filters. Always look for a brand that offers replacement parts.

Air pumps should be located higher than the aquarium water level so a power failure will not create a siphon condition that could bring water from the aquarium back to the air pump. Sometimes an extra length of airline tubing looped higher than the aquarium will safeguard the air pump in energy outages. Probably the best way to safeguard them is to install a suitable one-way flow valve on the outlet side of the pump.

Selection of properly sized air pumps is sometimes confusing. Most are rated in PSI, however a few are rated in cc/min, or l/hr, which only relates to the volume of air being delivered with no backpressure. PSI is an indicator of how far the pump is able to push air under the water, a much more useful term. A pump designated at 1 PSI would be able to push air to about a depth of 2 feet (60 cm). However, the deeper the air goes the less air flows because of backpressure. Keep in mind airstones and bends in the tubing also add to the backpressure. At about a 12 inch (30 cm) depth water pressure is .5 pounds. At 18 inches (45 cm) its about .7 pound and near 4 feet (120 cm) it's slightly less than 2 pounds. Since excess air can be bled-off, the size of the selected air pump should always be larger than required, which will probably save money in the long run.

There are also single and multi-outlet air pumps. The single outlet version will generally suffice for smaller aquarium systems or where only small amounts of air are required. Multi-outlet pumps are fine for larger systems or where more than one source of air is needed. Most air pumps should have a gang valve installed in line, especially where a slightly oversized unit is utilized, where one unused outlet can be used for venting excessive pressure.

As for diaphragm air pumps, look for ones having a sound absorbing casing and non-slip rubber feet, which helps to deaden their vibration/noise. There are also some that come equipped with air filters/carbon air filters, and/or a means to control the volume of air it produces - a nice touch.

Emergency Power

Have you ever been subjected to an electrical power loss? We have and having several aquariums during these outages made us think of how to limit some of the problem areas encountered during these timeframes. One of the simplest is to keep a battery operated air pump that uses two 'D' batteries, as that would provide some water movement and oxygen to the animals in the aquarium. And even though these units are not powerful enough to force air to an airstone at any significant depth, it will come in handy during an outage.

For those in colder climates, or those were severe storms cause far longer outages, both water movement and temperature control can be a major problem. In such cases recommend keeping a small 'inverter,' which is capable of converting DC power to AC. Then, during an outage, it can be connected to a car battery, or even better, a boat/marine battery and supply AC power to a small circulation pump and possibly a heater if necessary. Depending upon battery charge and size, and the equipment being powered, it could successfully take an aquarist through a major power outage.

Another more expensive solution would be a power generator, with those being powered by propane rather than natural gas or gasoline a better choice. There are many choices, from roll-around sized units to those permanently installed outside the home. In fact, I did some research on these units for our home, but decided that for the length of outages incurred over the past decade, they were not needed.

Yet, back in the 90's installed some solar powered cells and a small wind generator for an aquarium system in my home office. It was capable of supplying enough stored power in an emergency to run all aquarium equipment other than its chiller and lighting system. Nevertheless, after a couple of lightning strikes that power source became far too expensive to keep running and was removed! Was however, an interesting experiment!

Depending upon the value of your aquarium investment and the area in which you live, alternate power sources should be given some thought before experiencing an outage!


Lets now move to Chapter 3, Water Processing Equipment.