My tap water has less than 17 ppm of hardness. I have been using nylon bags of crushed coral to gently add some hardness to the water. Is this a good aproach? Joe Hildreth 15 Cedar Street Potsdam,NY 13676 ------------------------------------------------------------------------- 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"!