inverts...shrimp or dwarf crayfish?

[fish 'n' fries]

I'm planning a couple small planted tanks and debating if they can have any nonplant life. How small a tank would you think of putting inverts in?

I'm thinking specifically about cherry red shrimp or dwarf crayfish (saw some at a LFS--and I'm easily influenced apparently ).

I'm not worried about size from the stability aspect--I've done small tanks before without difficulty. I just have no idea what volumes are considered needed for inverts. Are there any guidelines like x amount of water per individual or such? Thanks.

 

[theotheragentm]

Both are very small invertebrates and the bioload they create is quite small. I think moving room is more of the issue. If they have enough room to move, the bioload won't be the issue.