The suckers on my filter decided not to suck last night and it kept floating on the surface. It's an air-driven penn plax smallworld filter but I have the air flow set low. Because I had no time to deal with it last night, and it makes lots of noise when it floats and I doubt it would work properly, I switched it off for the night. This morning there was a big bubble nest. It is only the second time Archimedes has built a bubble nest and the first was the second day I had him, before I put the filter in.
Do you think this means he prefers not to have the filter? The air is set low and the water is pretty quiet for him but what water disturbance there is is near the top, so maybe he's just not able to build one when its on? Or maybe he doesn't like to go near the top too much when its on?
He's in a five gallon bowl, if I decided to remove the filter how often would I have to change the water? At the moment I do it weekly.

I noticed the same thing with my bettas (and gouramis) when there was filtration, I think they may just be unable to build the nests in moving water. Sometimes if you put in a floating plant they will make one within the leaves.

As for how often to change the water, when I kept bettas I did it about every 3 days (usually 25-50% water changes) and whenever I felt necessary I'd completely change the water. It depends on a few factors, such as what you're feeding, if there are live plants, etc.

Chrissy

Well I turned the filter off again to see what happened and he built another bubble nest. I think I'm going to give it a go without a filter for a while and check the water daily. It'll mean more water changes but it's only a small bowl so 50 per cent changes don't take hardly any time at all. He doesn't have live plants, only silk. He has some that float but he doesn't use them for bubble nests at all.