I found my old 20G from 20 years ago (which I used to keep Malawi Cichlid juvies at my office). Skeptical, I filled it with water and left it outside... and it held!

I have an old undergravel filter in it -- best wisdom we had at the time. I was thinking of just leaving it in and covering it with substrate (not actually hooking it up) rather than spend $15 on another sheet of eggcrate to protect the glass bottom. I'm not going to rock it super-heavily as a grow-out tank but I like to be careful.

I'll throw a canister or HOB on it for the actual filtratiion.

Any reason not to do this? Anything bad that could collect underneath that wouldn;t do so with eggcrate?

Thanks!

If you use gravel I would think poop would collect under it. Really really good gravel vac may work.
And if sand is used I guess you would have to watch out for air pockets that could get trapped.
And it sounds like weight wont be a issue, so you should be good to go there.
Guesses on my part..

I know someone with better knowledge will be of more help.

Leslianne

I agree with labama's thoughts. It might be more trouble than it's worth.

If you don't want to buy a full sheet of eggcrate for a 20 gallon and still wanted something for peace of mind, you could use styrofoam under the rocks.

totally agree with aura on the styrofoam