Saltcorner
By Bob Goemans
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Bob Goemans corresponds with César Silvério (Portugal)

César Silvério (Portugal) writes...

Dear Dr. Bob Goemans

After more than fifteen years of keeping discus, I have decided about one year ago, to try a reef tank. In the next six months I will move to a new house and intend to install my first reef aquarium. When I decided to become a reef keeper, I begun reviewing the magazines (FAMA and TFH) that I have subscribed to during the last five years. I ordered some books in order to prepare my entry in this new world. I have now in my computer a database of more than 250 different themes.

Among those articles and books I must say your lessons in Sand-Mail and Julian Sprung's Reef Notes, both in FAMA and your booklets "Live Sand Secrets" and "Marine Algae Control Secrets" and both volumes of "The Reef Aquarium" by Julian Sprung are excellent!

I feel in this moment I am "almost ready" but as you are in my opinion the greatest opinion leader in this hobby and some doubts still remain, I would like to ask for your help and comments on the set-up I plan to install:

Aquarium dimensions: 150cm L x 65cm W x 65cm H with overflow. I intend to install a plenum in a sump. The plenum will be built as follows: Eggcrate - 1" deep with two inches of sand, then the dividing screen, then two more inches of same type sand.

About the plenum I have my first questions:

1. In your booklet you mention that the "rule of thumb" for a plenum in a sump is that the sump have more or less two thirds of the surface of the main tank. Do you think I can handle this tank having a sump with 85 cm L x 45 cm W? My idea is using one of my old cabinets.

2. In the same booklet you refer to an aquarist having excellent results in nitrate reduction by using a water flow rate of 15 gallons per hour for a 30 gallon auxiliary tank. What is the pump ideal flow rate for my tank and what would be the maximum flow rate allowed?

I intend to install in my aquarium a calcium reactor and a protein skimmer and I have two more doubts:

1 - When replacing the evaporated water, shall I use RO/DI water only, or shall I correct it with any additives?

2 - The protein skimmers readily available in Portugal are: Turbo Berlin (Red Sea), Turbofloter 1000 (Aqua Medic), Automatic Skimmer 230/3 - (Tunze, and they claim to be "plankton safe." What would you choose?

In the show tank I intend to install a 1" deep sand bed, is that ok?

Going to illumination, I intend to install a device with two 250W, 10K German metal halide bulbs, and two 30W fluorescent actinic bulbs. Do you think this will be enough to keep soft and stony corals and other inverts? If available should I choose 20K metal halide bulbs?

Regarding the powerheads, how many, with what flow rate, and what would be the ideal position for them?

Is there any trademark plankton safe?

In Portugal I don't have the possibility of getting live sand, so I intend to order from USA, some of Marc Weiss products to help start my aquarium; what are the products that you would advise?

As you can see for a person "almost ready" I have a lot a doubts; I hope you will be patient enough to help me!

Thanks in advance for your help.

César Silvério

Portugal

Bob replies...

Dear César,

Thank you for your kind remarks and let me note that I prefer to be addressed as 'Bob' not Dr. Goemans. My doctorate is not in the medical field, and feel that 'Dr.' should be more properly applied to those with a medical degree.

Let me address first your decision/question to place the plenum in an interconnected tank, i.e., auxiliary plenum system. This method has become widely accepted, as many aquarists simply do not like the look of a very deep bed in their main system. Not only has it resolved that issue, it is proving to be more easily maintained when not cluttered with live rock formations and various coral animals. My old 180 gallon solar powered reef aquarium had a 60 gallon plenum tank under the main tank. However, that main tank had 27 fishes and was fed as many as six times a day. I found that size interconnected plenum system not capable of keeping nitrates below 5 ppm, as originally desired. Its nitrate level stayed about 7 to 8 ppm. Therefore, it only seems reasonable to assume a slightly bigger plenum system or less feeding would have reached that goal. Because of this personal experience, I now think the interconnected plenum system not be any smaller than half the size of the main tank when it comes to surface area. And yours should do nicely! Of course many aquarists don't feed that often, but I couldn't pass up all my little friends every time I passed by without giving them a treat. Besides, I was using a new phosphate removing product from England called ROWAphos that is quite remarkable. I was also using the Merck Test Kit 1.14445.0001, which is without doubt extremely accurate. Keep phosphate below 0.015 ppm and you'll never be bothered with unwanted forms of algae! And this is the only somewhat reasonably priced kit that I know of that will accurately measure this extremely low level.

As for flow rate between the plenum tank and main system, feedback and personal experience show that something near half its volume per hour seems to work the best. If your auxiliary plenum tank is about 80 gallons, then forty gallons per hour should flow between them. Again, this seems to work the best for everyone that has tried it, yet flow could be somewhat more or less.

My preference for makeup water continues to be just plain RO/DI water, with no additives. I am not comfortable with the wide array of additives on the market. Not because they are of inferior quality, but because of improper use! Too many aquarists think a little more is better when it come to dosage rates. Not true, and confusion remains about their need. Often, there's duplication of various elements and compounds and that leads to precipitation of much of it. And, if there is a calcium reactor in use, much of what would be added to RO/DI water is duplicated in the reactor's effluent. Yet, in certain circumstances, these RO/DI additives do have a good value, however, each system should be evaluated as to their need.

When it comes to the three available skimmer brands, I or my clients have or are using all of them. They are all excellent products, however, you are right about the more plankton safe Tunze models. If that's a concern, the Tunze model would be an excellent choice.

When it comes to the depth of the sandbed in the show tank, I've done almost the same thing in my old 180 system. In some places it was about two inches deep and sand grain size was about 2 mm.

As for lighting, your six foot system will probably need three 250W 10K MH lamps and possibly two full length 50/50 type fluorescent lamps to adequately light the entire tank. However, for now, more light loving corals could be grouped near the two MH lamps and those animals not needing bright light placed in the lower light areas. It all depends upon your ability to pay the electric bill! And I've found the 20K lamps to make the environment look too blue. I prefer the 10K's. Of course either would suffice for the animals, but to the human eye, my preference is the 10K's.

When it comes to powerheads, I've grown to like the various models in the Tunze line. I've had great success with them, however, they are quite pricey when compared to other brands. As for placement, the rear corners are two of the best places with each facing forward and slightly to the center of the aquarium. Placing them on a wavemaker so as to alternate their flows is the best approach, and the Tunze units are built to handle the on/off routine without any heat buildup or additional wear. My reef system also used two Tunze Turbelle 3000/2 system pumps for consistent water movement in the aquarium. With each Tunze capable of delivering about 700+ gallons per hour, system surges could at times exceed 2000 gallons per hour. And that's not counting the flow from my interconnected plenum system. That entire system can be seen by visiting my new website at www.saltcorner.com and clicking on the Photo Gallery button (the lower right button). Which by the way could contain system photos of your system (or others) if they become available to me.

I should also note the flows that impact the animals must be related to what they would incur in the wild. That's not easy to judge, but commonsense should be used. System overall water movement is more of a general concept that helps with preventing dead spots and providing good gas exchange. It should never be confused with direct flow against or around an animal.

As for 'live' plankton foodstuffs, I'm not sure what's available in your area. Yet, caution must be used when using any live foodstuffs as unwanted organisms can easily be introduced. My preference is would products such as Julian Sprung's Marine Snow, Marc Wiess Combo-Vital and/or Kent Marines Chromaplex Phytoplankton/Phytoplex Phytoplankton. Also there is a new phytoplankton product called BioPlankton from Liquid Life USA. You can check it out by visiting my website and clicking on their banner on the advertisers page.

For starting the microbial processes, there are many excellent products. And if possible, an aquarium's sandbed should be microbially well established before adding too much live rock. Starting a system with more nutrients than what there is in the way of bacteria to use them simply does not make sense! Why give unwanted forms of algae an opportunity to gain a foothold. Get the nutrient 'users' established first, then introduce a supply of their needs. Patience pays off in the long-term! And, could be the sand your going to order is available 'live.' Some of these prepackaged brand sand grains are already coated with bacteria. Even though dormant, these bacteria will quickly awaken and begin colonizing the substrate. Check it out!

Hope this helps and keep me posted,

Bob

Keywords:

Auxilary Plenum; Aquarium Setup Advice

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