Solar & Wind Powered Reef System (written in 2002)
by Bob Goemans
This is a system based on the collective knowledge gained over the past few decades and includes a novel way to power most of its equipment. Much thought went into its construction, as it would be a showcase in my new office that was a major expansion to our home in the Tucson Mountains.
With being able to look back in time I decided to take what has been learned and incorporate it into a new system that would decorate my new business office. I wanted something slightly nutrient rich, yet extremely easy to maintain. That’s probably not much different than the goals of most aquarists.
The new system’s environment would be somewhat lagoon-like at one end of the aquarium and reef-like at its opposite end. With foot traffic in my office consisting of city and county government officials, local school and university students and aquarium company representatives, something containing a fairly large fish load and yet looking quite reef-like was in order.
Moreover, I wanted a system that would never be endangered because of power outages. In the past we’ve experienced as many as 10 outages in one day. Setting up battery powered aerators and floating plastic bags of ice cubes during monsoon caused outages during the hottest months were something I no longer wanted to be concerned with. Since we live in a climate where there is sunshine better than 300 days a years, solar and wind generated electricity entered into the new system’s equation.
I decided on a new 180 gallon reef system that would contain a sandbed not more than 1 to 2 inches of aragonite ‘live’ sand. Using already live sand would quickly help enhance environmental conditions when animals and some sand/rock were moved from my older and overgrown 125 gallon plenum-equipped in the main tank system. The photo of that system can be seen in the ‘Coral Budding’ article on this website/Articles, which was taken about ten months prior to the move. By the time I was ready to move the animals, the Acropora yongei on the upper right had completely table-topped and I needed a hammer to get it out of the aquarium. In fact, its growth rate was so fast during the last few years I decided not to put any of it in the new system. I decided on a shallow bed in the new main tank with an interconnected 60 gallon plenum-equipped tank below the main system. One of the better aspects found during the past few years were that a shallow sandbed is much better than a deep sandbed directly on the aquarium bottom. No matter what you hear about deep beds, the fact remains they mostly foster anaerobic conditions where no beneficial oxygen exists and this leads to a form of denitrification called ammonification that generates ammonium as its end product. And algae prefer this nitrogen product over that of nitrate.
Since power outages were being brought into the equation it was necessary to prioritize system equipment and fit their energy requirements into a reasonably cost-effective solar and wind power budget. I say ‘reasonably’ because payback depends upon many things, such as how much sunshine and wind is experienced. With the emphasis on energy costs or even its availability these days, could be many reading these articles might also want to consider these methods to power ‘essential’ aquarium equipment. My goal was to stay with a system that could steadily supply about 260 watts and guarantee a supply of uninterrupted power for about two days.
Without a doubt the system’s various water pumps were the more important items. Not only the water pumps for the main aquarium, but also the pump in the remotely connected plenum tank. And, of course, power was needed to keep the protein skimmer running as it keeps system redox high and bulk water well oxygenated. Power to supply lighting needs at this point in time was out of the question. Besides, it’s not vital in short-term power outages.
Before going any further let me say that my new aquarium contains a rear vertical sump across most of its backside containing an overflow standpipe. The good part about a rear vertical sump area is that system pump(s) installed there can be low wattage devices and still deliver very good water movement. The poor part about a rear vertical sump area is the aquarium’s front to rear depth is reduced, however, good aquascaping mostly overcame this reduction in depth. Notice some of the quad outlets on the wall under the tank/sump area (The left side of each outlet provides solar/wind energy, and right outlets provide electricity from the local electric company.) and the large removable doors on the stand for easy access when needed.
Keep in mind those systems with the sump located below the tank need much bigger electrically hungry pumps to overcome head pressure in lifting water high enough to get it back to the tank. Since this aquarium will be equipped with two system pumps, only low wattage Tunze 3000 water pumps using 20 watts each were needed. Since each is mounted where there is minimum head pressure, each can deliver about 700 gallons per hour. Of course these pumps plug into solar-powered outlets, which are part of six quad outlets that service the aquarium area. There’s also one GFI quad solely powered by the local electric company and dedicated to aquarium lighting and chiller needs. In fact, the water pumps used on my protein skimmer, calcium reactor and that for the plenum tank use a total of 175 watts. That left some unused watts in my budget and they have mostly been applied to other small devices, such as electronic monitors and evaporation makeup equipment.
To stay within a reasonable solar budget I decided on purchasing four 75 watt photovoltaic panels mounted on a Zomeworks Passive Tracker. The tracker automatically, with no use of any electrical power, follows the changing angle of the Sun daily so as to get the most energy possible. Trace Engineering supplied the Combiner box, Charge Controller, Inverter, and the system has a remote control panel wall mounted in my office. Power is stored in eight car-like batteries, located in a small outside shed. The wind generator is a Southwest Windpower 24VDC model 403 Industrial grade unit supplying up to 400 watts. These units only have two moving parts and generally only need a small amount of maintenance every few years.
As for other system equipment, there are two Tunze 2002 powerheads for additional water movement plugged into a wavemaker, which have all worked flawlessly over the past 5 years on the previous system. These pumps each provide an additional 700 gallons of water movement and at times this new system could experience about 2000 gallons of flow. These units are designed to take the on-off use associated with wavemakers. Each is mounted in the rear top corner of the aquarium, as they were in my old 125 gallon system. Their body sits above the aquarium with its drive shaft and impeller protruding through a drilled hole in the top corner surface of the aquarium. I should note they can be mounted similar to powerheads, i.e., over the edge of the aquarium, but found it more convenient to place them this way because of the wide top edge on acrylic aquariums.
Lighting consists of two 250 W 10K metal halides, two 30 watt 50/50 fluorescent lamps, and three 55 W PC lamps. The chiller’s drop-in probe is located in the rear vertical sump, right in front of the water discharged by one of the two system pumps. Lighting and chiller plug into the GFI circuit.
When it came time to move some of the animals to the new system I had thought it could be accomplished in one day. However, moving ‘day’ actually became ‘moving days.’ I started on a Friday by hammering and chiseling out a good portion of my stony corals. I had such great success with various types of Acropora that I decided not to keep those species in the new system. That may sound odd, but after numerous trimmings I no longer wanted such stout bodied corals in the new system. If fact, I gave all my Acropora corals to a local store. One had table-topped into a section about 10 inches by 15 inches. It was blocking light to other corals and made it difficult to clean the sandbed in that portion of the aquarium. It also reduced water flow in that part of the tank. Instead, I kept some of my Montipora specimens and moved them to the new system. I say some because some had formed mounds that had to be chiseled out and those were also given to the local store. After removing these corals and adding some make-up water, that was it for day one. On Saturday other corals and some live rock were transferred to the new system and arranged to fit my planned aquascaping. Water from the new tank, which had risen slightly from those additions, was transferred to the old tank. On Sunday the fishes I wanted to keep were transferred to the new system as they were now fairly easy to catch and those I didn’t want were given to the same local store. Two cleaner shrimps, a large red brittlestar, ten snails and a few hermit crabs were also moved to the new system. The last few pieces of rock were then moved and some live sand transferred to the new system’s plenum tank. Actually, this all sounds a lot easier than it was!
I also moved all my Green Chromis, C. viridis to the new system and added six more. They are schoolers, very peaceful and look quite nice in small groups. I did not move my Purple Tang or Red Sea Sailfin Tang. They were becoming destructive in the old system and were such hogs that hand feeding any coral became impossible. Instead, I decided on only one Yellow Tang because of its more eye-catching color. I chose to add only one as more than one Tang shaped the same usually creates stress. Instead of other similar shaped Tangs, I chose P. hepatus, the Regal/Blue Tang and put three small ones in the new system. They get along with each other quite nicely. Of course, I moved my wife’s favorite fish, a clownfish, A. ocellaris into the new system. Also moved were a mated pair of P. kauderni, Banggai/High Fin Cardinalfish. One female Bicolor Anthias was moved and have since added a second. Currently I’m searching for a supermale. Altogether there are 17 fishes, and will probably add six to ten more Chromis, and the supermale before I consider the bioload complete.
I can reach about 90% or more of the sandbed surface in the main system because I’ve used branching rock that interconnects in a bridge-like structure across the entire back of the aquarium. Sixty pounds of the rock is from the previous system and two large pieces, just added, weighing about another twenty pounds. So the entire 180 gallon system holds about eighty pounds of rock. The main system’s sandbed is only about 1 – 2 inches deep and its was a good thing I did as the shallow bed began to cake-up a couple of weeks after I started up a calcium reactor I was testing. I simply took a chopstick, taken home after a dinner at a local Chinese restaurant, and ran it through the bed and crumbled the binding portions. I then found the bed in the plenum system doing the same. Since its surface is totally unencumbered it was real easy to breakup the forming crust and have since readjusted the calcium reactor carbon dioxide bubble rate and effluent rate and have not had any further problems. Nevertheless, I continue to check the beds every few weeks. That should be a lesson learned to those having systems looking like a rock pyramid. Having this wide-open expanse saved me a lot of headaches further down the road. Live and learn — hopefully!
I should note the large pieces of branching rock were purchased as dead, bleached coral so I would not introduce any bristle worms into this new system. There were none in my past system, and I want this one to remain the same. My clams will be safer if I don’t have any of these pests in this system. Nevertheless, the phosphate these two pieces of bleached coral contained did cause some cyanobacteria problems for the first few weeks. I added some additional Astraea snails and along with siphoning out the excess cyanobacteria on these pieces the problem was over in three weeks. They are now being coated with coralline algae and look quite nice.
Notice the Colt Coral-looking soft coral on the front left side. That is actually Nephteidae arboreum, called African Tree. Its extremely rare these days and what you are looking at is actually a cutting from a cutting I gave a friend many years ago. When he heard I was starting this system he offered me a cutting from his tank.