Instruct: Classify Amazon reviews into positive or negative sentiment
Query: The Tetra Whisper Air pump 60 Gal.

Received the Tetra Whisper pump from Amazon, hooked it up to my undergravel filter on my 36 gal. fish tank five months ago and it's been working great. I took someone's advice and hooked a airstone to the gang valve that the air pump supplies air to so there wouldn't be back pressure on the pump. Hope that will help prolong the life of the pump. I was so satisfied I ordered another one for a backup. There's a little hum that comes from the pump, Ive got it sitting on a old mouse pad. It seems to help.