Arthit, the KH/pH lower will lower the KH as well as the pH. However it is not lowering the general hardness of the water. So you will still have to get a RO unit if you want to lower the hardness of your tap water. Eric How about if I keep on with the KH/pH lower products like Tetra's? Does it actually reduce KH or just give out strong acid? What is its disadvantage apart from its price? Cheers, Arthit Bangkok, Thailand. ------------------------------------------------------------------------- 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.