are you talking abotu an undergravel filter?? there is a tray that sits under the gravel with a tube that comes up near the surface of the water and it has a little doohicky that sucks water up the tube and disperses it into the rest of the tank??
if thats the case, take it out. all it does is trap poo and yuck under that tray where you cant reach it without breaking down the whole tank. ugly things. they have a nice purpose in having a really stable biological filtration BUT the trade off of not being able to suck the poo out isnt worth it.
Chris- Husband, 04/30/77
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