An air pump that loses power or gets very loud may have a bad rubber diaphragm. These parts are located inside the pump. Just remove the screws on the bottom of the pump to open it up. The round rubber disk is the diaphragm. Each pump has a lifetime-limited warranty for manufacturing defects. Water damage does not fall under the warranty. So make sure you are using a drip loop and in-line check valve. If you cannot do this, make sure the pump is higher than the aquarium. Also, the pump is for indoor use only. The rubber parts, such as the diaphragm, are considered a “wear and tear” item. The life of the rubber parts depends on the application. For example, a diaphragm running a one-inch air stone will last much longer than one running a twelve-inch bubble wand. These parts will need to be replaced over time and are not covered by the warranty.
Many replacement parts are available in our Tetra online product catalog. Check there for the ones you need. If you have questions about replacement parts, please call us at 1-800-423-6458 between 7:00 a.m. and 9:00 p.m. EDT.