His other home is a 1 gallon that I just ordered java moss for. It's deep enough that I can put a heater stick in when the weather gets cold (which it doesn't do much in Florida, really). And I think he likes the variety.
Oops, I reread my response and I made a boo boo. The bowl he is in in the pic is 1 gallon. His other home is 2.5 gallon. Yeah, 1 gallon is too small for a permanent home I think. And for Jspigs, room temp. here in Florida is 78 or above ;-).
I use one on my 2.5 gallon Betta tank and it works great! The flow from the filter is not to strong for my Betta even on full flow. One thing I did was I added extra bio-media (those little ceramic cylinders). Don't listen to the instructions when they tell you to replace the sponge because if you replace the sponge you are throwing out your beneficial bacteria.
Also instead of buying those replacement filter pads just buy a bag of filter floss and user that as a replacement for the filter floss pad provided.