Tetra Whisper Air Pump - Ultra Quiet Aquarium Air Pump with High Oxygen Output for Fish Tanks, Ponds & Hydroponics | Perfect for Home Aquariums, Fish Breeding & Oxygenation

I first began using Whisper air pumps as a child over thirty years ago. (Back then they were tan and the air filter could be popped out.) They were the best then and I am pleased to say that I find them to be the best now. I am using the Whisper 20 for an over stocked ten gallon tank. It is working very well to supply a large air stone. This pump was a replacement for an identical pump that was eight years old.The old pump had lost its power, but it was still going strong and it was ever so quiet. This new one is doubly powerful. I had no idea I had lost so much performance with the old one. I know I could have purchased a parts kit to fix the old one, but it was just easier and less hassle to buy a new one. The new pump is slightly louder than the under performing old pump, but the difference is negligible. I would expect no less of a brand new replacement device with about double the output of the old device.I am very happy with my purchase. I highly recommend this product for performance, longevity and silence.UPDATE September 30, 2021 - Just a few comments concerning longevity. I have purchased this pump from Amazon three times. This most recent third purchase a couple days ago was to replace my second pump which LASTED OVER 7 YEARS!! - That’s a pretty good run. While the old pump still did work, it had developed a terrible rattle.I noticed the new model says it’s for 10-30 gallons as opposed to 10-20 gallons like the older model. They’ve updated the color from blue to charcoal gray. (See my side by side photos of the old model on the left and the new on the right.) - I think they have phased out the 10-20 version. I didn't notice a change in air pressure on my tank. HOWEVER, IF YOU ARE CONCERNED ABOUT THIS PUMP DELIVERING A HIGHER PRESSURE, PLEASE NOTE THAT THERE IS NOW A VALVE INCLUDED TO ADJUST PRESSURE.And THEY HAVE NOW INCLUDED A CHECK VALVE. It’s really about time they did that because it’s a cheap fix to prevent tank water siphoning into the pump if the power goes out. That’s a disaster in the making. The valve even has an arrow to indicate which way the air flow should go (please notice my photo). If you are new to keeping fish, for safety reasons: Please keep in mind to always use a check valve, no matter where you position your pump.