nah, none of mine are. then again, only one of my tanks has a filter, and that's Caroline's. my tanks are all under 5 gallons, with 3 gallons being my biggest, and one gallon being my smallest. i have a Plakat female in that one gallon, who seems to hate larger tanks. they stress her out and she hides all the time, but swims around happily in her one gallon. o.0 i've an oddball fish.