I did a 80% vacuum/water change in the 29 gallon (my aching back!!!), replaced the carbon filter section (3-part filter) washed the filter w/ HOT water & bleached the intake (it was gunked up from the oto's seaweed). I have the filter going full blast. I want to fast the girls, but I have to feed my catfish and the girls get into the wafers/pellets.
As for QTing, everyone looks fine. A couple were more stressed by the water change than others who are used to it. Some are so casual that they wind up in the gravel vac, so I cupped those. (My cat drank one of the cupped fish's water while I was dumping water-great-it was medicated!) I'm stopping meds & exotic food & see what happens next.
Anyone contemplating getting a bigger tank- it's easy to get the water out. It's refilling that is the killer!!!!