Are you referring to undergravel filters? If so i have used them before. I ran one in my 55 gal tank for a year or so and after seeing what grows under the plates i would advise you not to use one. I didn't have any problems with the tank or anything, but i can see issues arrising after long term use. The gravel is so much cleaner and easier to clean without those plates there. Plus you have the tacky upflow tubes. My advise is to just use a good HOB filter and a few powerheads.
