In a message dated 4/25/03 12:11:15 AM, caw18@bak.rr.com writes: << o around 8.4! I tested the KH, and it is still at 2 or less in some cases. So what is driving the PH up? I have ruled out the gravel and the sand, >> Not necessarily correct. The gravel is very suspect when you get to lowered TDS with RO water. The clay pots cannot be ruled out either. How did you test the gravel? Lee Harper Media, PA USA ----------------------------------------------------------------------- -- 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. apisto-digest@listbox.com also available. Web archives at http://lists.thekrib.com/apisto Trading at http://blox.dropship.org/mailman/listinfo/apisto_trader