So, I know for sure I am going to get a small 2.5 gallon tank per male betta, I was interested in opinions. Would a sponge filter be better or a hang on filter?
It was made for a vase, as SRC said, and I think it would be okay for a 2.5 gallon tank. I notice that sponge filters are cheaper, but does that make them better or worse? or is it an opinion thing?
They both work well. Basically you're just looking for a media to grow beneficial bacteria and force the water flow through. That link is dead. I wanna see a vase filter
Oooh yeah! I forgot about those cute itty bitties. I have two of them somewhere. They were great way back when I used them. If they'll fit properly on your tank I would definitely go for them instead of a sponge