Check the "Changing Substrate of an established fully planted Tank?" topic
which I posted few weeks back.

I am changing my substrate of an established tank to 100% Fluorite. I am
changing 1 foot every weekend. First time I had little bit of Ammonia spike
because of the disturbance. I changed 50% of water and it was ok.

--
Thank You

Dominic
http://www.dlink.org/aqua

"John Worfin" wrote in message
. net...
Has anyone attempted to remove and replace portions of the gravel of their
tank, without first tearing the tank down?

I have larger gravel (about 1/4") and would like to replace some of it
with
a layer of finer pebbles.

Is there a trick to doing this?