Because all of the ammonium is then ammonia and unusable to the bacteria. It could be the reverse but I am about 90% sure that biological activity ceases at 5.0 pH. >Scott writes: > >> Bio filters are not functional at a pH of 5.0 are they? > >Why not? Sure they are. > >Bob Dixon >Cichlid Trader List Administrator >http://cichlidtrader.listbot.com > > >------------------------------------------------------------------------- >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"! > > -------------------------- Aye Net WebMail 2.0 http://www.aye.net/getmail ------------------------------------------------------------------------- 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"!