I had an acrylic tank setup in my garage for several years. Tank was around 200 gal and I used a 100 gal stock tank 3/4 full of lava rock for a sump. I tore that system down when my son who was 2 at the time dumped ATF in the sump, and killed the fish. Now I am getting the itch to build a larger plywood tank. I can go 10X4X4 if I set it up right on the floor with no stand. I have several ?'s though. Swimming pool filtration is pretty well a given instead of a sump like my previous system. Would it be a good idea to lift it a few in off the floor and put in a central drain, or should I just go with a skimmer box on 1 end? If I put in a central drain I plan on raising a small area around it about 6", because I want to have a deep substrate bed, and know that the drain itself needs to be above the substrate. Whats the best product to seal the tank with that is not gonna cost me several hundred $$ just to seal it up? Is 3/4" plywood with 2X4 studs every 2" ok, or should I go closer together with the studs? I have an oceanic 100 that I can cut apart. The glass is 1/2". Would the front and back pannels from that tank be good enough for viewing windows in the front of my tank, or should I just buy a large sheet of acrylic and make 1 3' X 6' window? If I go with acrylic how thick should I go?