I'm new to this aquarium thing, but I would like to add that the author of
the
book "The Ecology of the Planted Aquarium" does 50% water changes every six
months or so.

I've heard that, but I don't understand how she avoids pH crashes that way.
Don't biological processes use up all the KH in the tank in six months? Even
if you don't have a lot of fish, you still have bacteria, decaying leaves, etc.

As for my tanks...I change at least 30% weekly. The fish seem to appreciate
it, even though my tanks are planted.


Leigh

http://www.fortunecity.com/lavender/halloween/881/