Sorry Lisa I obviously gave the wrong impression. Whatever you are doing, its clearly working.... so, no argument there.
The experience I am drawing from was being advised early on to put gravel on the bottom, which I did ... a kinda thick layer actually..... and it turned into a cesspool. It actually smelled bad (anaerobic bacteria). This woman had told me that you want a lot of rocks so that beneficial bacteria would live and that I wouldn't have to clean it just use the aquascape sludge cleaner product
Other factors contributing (and no, it wasn't only the prescence of gravel that was the problem) was inadequate filtration/water circulation down at the bottom.
I mention it only in the spirit of "comparing notes," not as criticism. More like... something to look out for. It makes sense that a thin layer would not have same problems. There are so many variables. Maybe had I had better filtration, less gravel, and/or used the sludge buster... I would've been successful. I instead just went a different route, for the reasons already mentioned.