Has anyone tried to add a hand full of crushed coral to raise and maintain
KH?

I used to put crushed oyster shell in the filter, to increase KH. I used the
kind that was sold for pet birds, and put it a mesh bag in the media box of the
filter.

I set up a new tank and my hardness is 1 the PH is 6 and I want to add CO2
but fear that the PH will drop.

If you use Onyx as a substrate, you'll never have to worry about low pH.


Leigh

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