I had an impulse buy today, and now I'm trying to set up a 3.5 gallon for him to live in. The tank came with a little bitty HOB filter. I do not have a cartridge for it right now, but I can get one soon. I would like to go ahead and put the betta in, but does he need the filter right now? It's pretty strong with nothing in it.
I know cycling a 3 gallon is very controversial, but i have cycled this one before... However, I'm not sure whether I will again. For now, what water changes should I make?