I bought a used aquarium and it came with an Eheim pro 2227 canister setup. This is the one with the wet/dry system. It is setup so that it cycles the water flow on and off with a float system.

The question is... When I first set it up, it seemed to work fine, but now it is "gargling". It does this when the float goes to the bottom of the chamber. A little bit of water gets into the third small hose. It's not from the aquarium end, it's from the filter end...

I'm going to replace the seal on the end of the Styrofoam float (what a hassle), but any other ideas?

John S.