Boy am i glad im just a hobbyest with really good tap water, because you people are losing me with all this water chemistry. I have soft soft slightly acidic water out of my tap. My fish breed in it, heck Discus breed in it with no problems. I dont need a R/O unit where i live, thank god!! If I had to figure microsemions because i had hard water, i'd keep rift lake stuff! 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"!