Nyssa 3 At first, the pump was perfect. So quiet, and good for my shrimp tank. I think it is good for nanotanks and for tanks in lobbies or offices where there is a lot of noise. Over a couple weeks, it is slowly getting louder and louder. It makes a dissonant chord with my other electronics (air conditioner, refrigerator, fan) and it’s difficult to ignore. I will buy a different pump.