My dilemma was this. Although I knew it would be the easier route to build a concrete
tank, I didn't want anything that permanent. I knew I wouldn't tire of the tank, but what if I sold the
house? What would it do to my resale value? I came to the realization that not everyone wants a 1700
gallon shark tank in their basement, and tearing out concrete would be a nightmare. I would have to make
it removable, this meant building it from a material that would lend itself easily to disassembly.
The obvious choice was wood. The plans on garf were great, but simply would not be practical on a tank
this long, and deep and BIG. With depth and length, comes pressure. Without some additional support and
structural rigidity, a plywood tank would literally blow apart. The challenge with any aquarium whether
it be glass, acrylic, wood or cement, is building the walls to withstand forces generated by the water
pressure. The deeper the water, the higher the pressure per square inch. Dealing with this pressure
means preventing warpage/bowing. In smaller tanks, this can be accomplished by increasing the thickness
of the glass/acrylic, and adding support (cross bracing) to the top of the tank. Cross bracing alone,
would not solve all of my problems I had to find other means to help prevent bowing and flex.
I knew that the garf plans had worked for many, as long as they were sealed properly. I knew plywood
walls coated in epoxy would work. The way I saw it, I had two obstacles to overcome.
My basic plan, was to build a boat, but inside out.
- Supporting the entire tank so it wouldn't unfold like a cardboard box when full.
- Sealing the seams, and preventing them from splitting/leaking under pressure.
Support: I decided the best way to prevent bowing, would be to support the tank from the outside, using
interlocking 4x4's as support bands. Basically, the tank would be encased in a wood skeleton, adding
strength and support in all the high stress areas. So the tank would still be a plywood tank, with
regular plywood walls, but reinforced from top to bottom, with the most reinforcement at the top. To do
this, I would need to build the frame first, and in a sense, install the tank last.