Does anyone here have an under-gravel filter set up in there tank?..and if so,is it working effectively? I ask because I've had one in one of my tanks for a few months(in addition to a Whisper power filter) and it doesn't appear to be all that effective..I want to believe I have it set up correctly since I'm reasonably good at assembling stuff as per instructions..however,in the space of 4 days I found two dead fish in that tank(on a sad note,they were 2 of my 4 Glo-fish)..I decided to a major clean-out of that tank and you would not believe the build-up of foul smelling crud I found under the under-gravel filter panels!..even with the occasional stirring of gravel that is required in addition to numerous water changes and vacuumings,the bottom of that tank was a sorry mess..the only thing I can think of is the air-pump I had attached to the under-gravel filter wasn't strong enough.
Thankfully,the rest of the inhabitants of that tank appear to be healthy...fingers crossed.