Hi, I bought a new filter about 3 months ago, It started making a sqeeking sound about two weeks ago. Every time I do a water change I see a little bit of sand in the fiter, I tried cleaning it out real good but can't get it to stop making the squeeking noise. I think theirs sand inside it!!!! So i went to the store and bought a new one, I'm hoping I don't have to do this every 3-4 months. Anybody have any solutions???? Thanks....