it puzzles me why in the latest messages only KH is mentioned and no mention at all of Gh or even total hardness. also I saw mention of increasing Co2 to lower Kh. I would have thought this would have more effect on pH than Kh. cheers Neil _\\|//_ ('o-o') -----------------ooO-(_)-Ooo----------------- http://users.gravity.net.au/travisn/