So I stand corrected by Penfan66's link and everyone else with experience in the matter. Serves me right for trusting what I read online.
I guess then it's only a problem if you believe it to be one, and maybe for replanting.
I have UGF with amazon swords, and they are growing like crazy, you can see the roots growing underneath the filter plate, but it is definitely filtering the tank. I agree, it should be supplimented with a HOB filter
This is interesting....I am testing that theory on my 55 g, When I put the new substrate in I removed the 2 center plates, it actually seems like the ones on the outside are getting greener than the ones in the center..