Dick wrote in
:

Actually, I wonder why you believe the gravel needs cleaning? The
poster says nothing about any problems. His concern seems to be from
reading comments like yours. He may well have plants.

I accept your caution, but only as a caution, not proof of your
belief.


Belief? No. I have an unplanted tank, and my local water is normally soft
and acidic (low bufering capacity). When I vacuum the gravel during water
changes, I see a marked control in the rate at which total nitrates
develop, since I'm removing more decaying matter than I would by just
decanting off the supernatant water.
Without gravel vacuuming, fish waste continues to decay in the gravel
substrate, and nitrate levels rise more rapidly, requiring larger water
changes to keep nitrates 20 ppm. Its not belief... its math. But it is
also setup-specific, hence Tynk's wisely added caution. People don't
vacuum gravel on mere superstition, although Iunderstand how you might
think that about a lot of fishkeeping practices.

DaveZ
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