Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
I make a box out of 2 x 4 or other lumber that just fits the tank.
That stack of blocks is very stable.
2 blocks is not enough room for most canisters, though.
I use 2 stacks for tanks up to 4' long, no need for a stack in the middle.
If you are placing these on a hardwood floor or linoleum you might add a thin pad under them. They can scratch a floor. Look into something like a car mat, or plastic floor runner, or similar. Thin, so it won't deform, but sturdy.
Variations that would mean more room for a canister filter:
A) No shelf. Canister on the floor. Works just fine.
B) Use a 4" high block, then the shelf, then 2 x 8" blocks, and another 4". This is much better for a canister, and the tank ends up the same height as if you used 3 x 8" high blocks and a shelf. Ask for the 4" high blocks as 8-4-16.
C) Use 3 x 8" blocks above the shelf (+ the one below). This is better for shallow tanks. I have my 40 gal breeder on this sort of stack.