Hello Eric I no water specialist, but if you have hard water, just adding muriatic acid wont keep the pH down. I will bounce back up. YOu need a R/O unit to remove minerals, dissolved solids in your water that are keeping it hard and alkaline. If you really need to keep the pH down R/O unit is the best way to go, unless you want to move to Northeast or Northwest where the water is naturally soft and slightly acidic. John ------------------------------------------------------------------------- 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"!