I use this great pump for my pond and it has kept on pumping air and had no problem the entire time I've owned - over a year now.I use it in my 800 gal pond to pump air about 4 feet below the water surface. It is doing support service to the external water pump I have running water through the filters and waterfalls. I have the pond heavily stocked with over 20 12-18" koi. The water pump was previously the only aeration option I used, but after several episodes of pump failure and koi suffocation, I decided to shop around for an air pump to perform support duty to the water pump. I have used this Matala in that capacity, and it has provided faultless air delivery 24/7/365 for the past year or more. During this time, the pump has seized or failed several times, but my Koi have been happily oblivious because the Matala has kept the O2 levels up for hours, days or weeks while I dealt with the problem at my leisure, rather than having an emergency on my hands. Also, it has kept on going despite being exposed to the weather, including rain and heat typical of southern California. Highly recommended!Update 5/4/2018: Two years later and still going strong! Amazing product!