firefish

[justinl]

I would like a firefish and ive heard that they are quite the jumpers. However I don't wan't a lid that will cover up the top of my lid because I don't want to impede gas exchange at the surface. So my other solution would be to raise the rim of the tank by putting up a make shift sort of fence. my question is how high should it be so that i can be sure my fish won't clear it?