10g aquarium useful on a 90g fowlr?

[Justin_Toronto]

I just realized I have two 10g aquariums back at my parent's place from my youth... I did some measuring and that's about the largest I can fit under my 90g stand.. (there's a stud in the middle between the cabinet doors that stops anything longer.)

So I was wondering, could I use these for anything... or too small to be worth the expense of plumbing into a fuge or sump?

I currently just have a wet/dry with skimmer, and a canister... (plus live rock / rubble / sand)