>> The method I used to lower my GH was I did a 10 gallon water change (about >> 35%) with RO water every other day until I got it where it is now. > >Is the GH and KH going back up over time? Yes. I am going to test my rocks and gravel tomorrow to see if they are causing the buffering. I am concerned about using muriatic acid, since if I test a specific rock and find it is not the problem I would like to put it back in the tank. And I am worried that I won't be able to rinse all of the acid off. Would vinegar be safer? Will it even work? Thanks! Eric ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!