In trying to dig a bit deeper on where (pH) biological nitrification breaks down I came across this article which may be of interest with respect to which bacteria are in effect, and what "cycle your tank quick" products are doing. http://www.nickd.clara.net/artbacteria.htm ------------------------------------------------------------------------- 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"!