Just put one on my five gallon in which a betta will soon live...has anyone used it with a betta? I had a nightmare once with my Penguin 125 in which i found one of my bettas stuck on the filter and the resulting injuries eventually killed him. So needless to say I'm concerned about power filters and bettas. But the Whisper is a lot weaker, and can also be adjusted so I'm thinking of taking the chance.