I bought two Penn Plax Silent Air B11 from Amazon. One for my 25 then one for my 55 but split the hose so I have one on each end of the tank. They were super cheap and they work. They stay plugged in but once the power goes out the batteries kick in and the air starts coming out.There's a lot of ways to give your tank power while a power outage occurs. I recently purchased a generator for my fish tank but the problem is it's too loud to turn on at night if an outage occurs. Anyone have any reccomendations?

