George writes: > If you put in a box filter to remove the dark color, arn't you just > removing the tannins that you worked so hard to get? George > The tannins take on cations like CA and Mg in order to allow the release of the H+ ions that increase acidity. So when the carbon filter takes the tannins out, it takes out the other stuff, not the H+ ions. Bob Dixon ------------------------------------------------------------------------- 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"!