> This is something that I have been thinking about recently. I have a
> reef tank that has a lot of "live" rock in it. I is my understanding
> that live rock works at both nitrification and denitrification because
> it is porous. The enviornment changes from arobic (nitrifing) to
> anarobic(denitifing) the further towards the interior of the rock one
> "looks". I cann't see why this should not work for FW aquaria any
> better or worse especialy for fish that like a little hardness in the
> water.
I have a batch of fry that, due to a lack of tank space, are being raised
in a 5-gal bucket. In there w/ them are a few ramshorn snails and the rock
upon which their parents spawned them. This rock is a piece of lace rock
-- very porous -- and was in an aquarium for a very long time. The water
quality in this bucket has been very good, better even than my water
change schedule should make it (It *is* unfiltered water basically). My
thoughts are that this rock has a well-established bacterial colony on/in
it that is doing some nitrification/denitrification for me. Not sure how
to test this theory, but I think that that is what's going on. Sure seems
feasible.
> The second "filter" that comes to mind is a Jaubert setup which is
> another denitrifier used in SW tanks.
My outside aquariums have a deep substrate of sand and are "natural"
style. I know for a fact that there are some areas that go anaerobic, as I
have seen black on the substrate when removing the odd plant or two. I
also regularly find a large assortment of inverts in amongst the roots.
The coolest one was a small annellid worm that looked like a mini
earthworm. It was entwined in the roots of a large Crypt. :) I would
think that the anaerobic substrate would be detrimental to the
inhabitants, but I have *many* very healthy guppies in there and healthy
plants, and it seems a flourishing invert fauna as well. So it seems to me
that this may actually be a good thing in this particular tank. The
anaerobic areas are probably places in which some denitrification is
taking place -- I know I don't remove *nearly* enough w/ the (infrequent)
water changes I do on these tanks outside. :)
Julie <><