Join Date: Jul 2011
Location: Fort Myers, Floriduh
Adding a bit of crushed coral to your filter media will up both KH and GH as long as your pH in the tank is below 7.0. I have had KH-related pH crashes, but this was with a KH of 0. Added the crushed coral and voila! No more pH irregularities. I am sure that the KH was not the only possible cause, but the crushed coral did fix the problem. My tap water comes out with 0 KH and a GH of about 24 degrees. Never had any trouble due to GH though- at least that I know of. I do not frequently test the GH or KH these days though, because I have found that for the species of plants/fish/inverts I keep seem to really not care too much about TDS, GH or KH, except for possibly how they relate to the pH.
I even have duckweed in my water bong!