Hi, I'm no expert on water, but have you tested your pH? heavy planting, no losses of fish from extremely acidic conditions... Could you be getting a pH crash? Gary ------------------------------------------------------------------------- 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"!