Okay, so Freedy was really happy for a while with the filter turned off. He blew big bubblenests and I finally got him to flare this morning! But I noticed that the water gets gross in the tank REALLY fast without a filter (2.5 gallon tank). It had developed a bacterial film over the surface. Last time I turned the filter on, he freaked out and got stuck to it somehow, so I've had it off since then.
This time, I ended up changing 50% of the water, putting two layers of pantyhose over the filter and rubber-banding a filter cartridge to the outtake so that it wouldn't blow him around so much.
Is this alright for bettas? Will he be okay with a little water circulation or should I turn it off again?