in article , Felix at
wrote on 11/3/03 12:19 AM:

get
away with just taking the gravel out and doing a complete water
change
I'd do that and give it time to stabilize and check it again. Flourite is
too expensive to just chunk it. Also think of doing sand instead of gravel
over the flourite if you want to hide the flourite. That's what I did and
the plants love the sand!