After several weeks of research, both online and through LFS (local fish shop) employees, I came to the conclusion that the only ready to go tank I was going to be able to afford, along with all the necessary equipment, was going to be a standard 55gal. From my research I also gleaned that this was not going to be big enough for my needs, and that the height of these tanks makes it difficult to work with. It was time to change the direction of my quest.
I have worked with both glass and wood in the past. I have not worked with acrylic. The decision had been made, by myself, that I wanted about a 75-85gal tank with more depth front to back than standard tanks and less height so that the lighting would be more effective. The glass for such a project would be very heavy so I turned to an alternative. I discovered that the people at G.A.R.F. (Geothermal Aquaculture Research Foundation) were using plywood tanks with glass fronts for their grow out tanks. This seemed to me to be both economically sound and the fact that the tank could be made just about any size desired. GARF also had plans and a calculator to figure out exactly the dimensions of the plywood right on their site readily available. I pretty much followed their plans with a few exceptions that will be noted in this article. Here is a list of the materials I used to construct an 80gal/48"L x 24"W x 16"H tank:
The GARF Plywood Tank Construction plans are pretty straight forward and I ran into no hitches with the construction. The plans did call for a different type of glue. I opted for a glue that I was familiar with (Gorilla Brand) and that is 100% waterproof and very strong!! Here is a list of tools that I used for the tank construction (If you don't have a table saw or circular, you can get the wood cut where you purchased it):
The frontpiece was doweled at each joint with 2-3/8" dowelpins and clamped together overnight. If you opt for the Hardwood Front (obviously it does not have to be Oak) make sure the front is square before doweling together. This is slightly different than the GARF method which was to attach the front in four pieces. Allow the tank glue joints to cure completely before painting with the epoxy.
Some of the paint that GARF recommends is no longer available and in some instances illegal in some states. The Carboguard 891 Kit meets all the requirements for paint used in potable water situations. Do not use the thinner that is recommended for this epoxy kit. It is toxic to fish and fumes does not fully disipate. The manufacturer does not list wood as a medium on which to use this paint but it works very well on the plywood. I used 4 coats on the interior, the bottom and the back applying each coat after 24 hours of dry time between coats. The sides I finished with a Faux Marble concoction of my own using various green and white acrylic latex paints that I happened to have around. The acrylic was then overcoated with 4 coats of Varathane.
GARF is very careful to mention the fumes put out by this paint. It is fairly noxious and probably could cause some damage if inhaled for any length of time. I painted outside and with a fan blowing and was still not happy with the fumes. Definitely use a painters mask, and if possible one of the expensive ones with the filters in the mask. When and if I do this type project again I am thinking about using 1/8"Acrylite Plastic to line the tank instead of using the Epoxy paint. You could paint the interior of the tank with any suitable paint first and then install the Acrylite as sort of a skin on the inside and silicone the seams well. This will also help facilitate the use of equipment that is put in the tank with suction cups.
I allowed the the tank to completely cure for 48 hours before placing the glass in the tank. This said, I would recommend having the glass cut slightly shorter (1/4") than the length of the tank. The epoxy coats add up to a fairly thick skin in the tank and if the glass is cut exactly you may have the same problem I ran into and have to scrape some of the paint down to accommodate the glass. The epoxy dries very hard and is difficult to change after cured. The exterior was finished before I installed the glass. Then the glass front was installed.
If you are using a Plenum that is constructed in one piece, make sure that you do not put the top brace in place before you have the plenum fit, finished, and installed. I followed the GARF plan for assembling the plenum with the exception that I also used this opportunity to install a Controlled Plenum Wasting (CPW) system. This is not a new concept, but one that has been kicked around for years and has somewhat come back into vogue.
I am including both the substrate and the base rock in this article because I feel that they are part an parcel integral with the physical tank and the biological filtration system. The base rock (aragocrete) was made according to the GARF methods. I will include a few tips here, but there are is a lot of information on making your own reefrock online. Some links to these pages will be included in the Links page in this site.