"It seems to me that if you have to add on powerheads to make it work very well you may as well get a good canister filter"
Well of course, it needs a powerhead. A powerhead is part of the undergravel filter. The reason that I like using an UGF is the fact that the waste is drawn down into the gravel and where the roots of the plants can get at it. so far, I have had this aquarium for about 6 months, and have not had problems. Of course, I am changing out the water, use around 7-8 plants of various sizes/ages, keep a small amount of fish and it is about 40 gallons. I am not worried about waste building up and being a problem, my original topic was about creating "dead spots" in the gravel due to a rock. I had heard that placing large objects on the surface of the gravel over a UGF would disrupt how the UGF works. This thread is now off topic, and I am not interested in changing my filter set-up because someone does not like UGFs. Sorry.