Not silicone,it doesnt stick to wood very well usually fiberglass is used on the seams and over the wood.Then epoxy paint to waterproof it,make sure the paint is drinking water safe.
ya your right. here are some pics so far. im playing it extra safe and sealing up everything even the spots that will not even be in the water. well i gonna make it 6' long 5' wide and 4' high. so how many gal would that beeh1421 said:i wouldn't try it i woulp be worried about it leaching chemicals into the water and also not sealing good enough and rotting the plywood.
remember this tank will be holding alot of water and possibly some very expensive fish
imo its not worth it . Go with what def works
mike