My bowl bettas are fine when I do water changes. They even cooperate by going into their holding cups and nicely swimming into their nets after they have been aclimated for the once a week 100% change. I also change 50% during the week as well, and they don't really care.
The bettas in my ten gallon are well-behaved as well, and vacumning the substrate is very easy in there.
Now my 15g is a pain in the royal behind! First, it's heavily planted. Second, though most of my fish behave nicely and get out of the way of the vacumn, I have pygmy catfish and bridget rasboras, very tiny, at times annoying little fish. They like to take trips up the syphon tube and play in my waste bucket full of dirty tank water. So a substrate cleaning goes as follows: Suck up water, suck up fish, stop sucking water, try to find fish, find fish, net fish, put him back in the tank...Suck up water, suck up fish, ect...ect. I hate, I mean I HATE CLEANING MY DARN GRAVEL!!!! Sometimes I wonder if it wouldn't be easier to just net the catfish and the bridget rasboras and put them in a holding container, but then I look at my planted tank and cry because there's no way in H E double hockey sticks that I'm going to find all the fish in that. Tongs make my life only a tiny bit easier, but it's all ok, I love my tiny fish. I only wanna fry them when I clean my gravel.
