Impellers

Last year I bought a 75 gallon tank that came with two Whisper 30-60 filters, which hang from the back of the tank. Both were quite dirty and I had to clean them up a bit. Within about a month they started making a lot of noise - a real loud hum or vibration. I changed the impellers on both (pictured above) and it really helped for a while.

The impellers come in different shapes and sizes depending on which filter you own, so if you decide to replace them be sure you're getting the right impeller. They're very easy to replace. Unplug the filter, take off the water intake tube and you should find the old impeller attached to the bottom. The wear won't necessarily be easy to see, but attaching the new impeller should make an immediate difference as soon as you start the pump back up.

It worked great for mine for a while but recently the noise returned (about 9-10 months after I bought the replacement impellers). I once again bought new impellers but one of the filters started making the noise again within a couple of weeks. I think they're just old and had a lot of wear when the previous owner had them.

I decided to go ahead and buy a new filter for the 75.

This is a Penguin 350 from Marineland. I already have a couple of these running on other tanks, so I knew it would be reliable. I also use larger and smaller filters that hang from the back of the tank. They work for me because they're quiet and easy to maintain.