I use a CO2 drop checker to know for sure. I bought mine from Aquaticmagic on E-bay but, there's a local guy who makes acrylic ones that are supposed to work great. http://www.plantedtank.net/forums/swap-n-shop/44423-fs-co2-drop-checkers.html -Tara > Date: Mon, 5 Nov 2007 10:33:41 -0800> From: matt@wrongcrowd.com> To: > gsas-member@thekrib.com> Subject: Re: [GSAS-Member] CO2 Magic> > >> > 2. Is > there a way to add too much CO2? How do I know?> > > Dead fish.> > You *must > *have some kind of pH indicator, otherwise you are working blind.> > - MS> > _______________________________________________> GSAS-Member mailing list> > GSAS-Member@thekrib.com> http://lists.thekrib.com/mailman/listinfo/gsas-member _________________________________________________________________ Boo! Scare away worms, viruses and so much more! Try Windows Live OneCare! http://onecare.live.com/standard/en-us/purchase/trial.aspx?s_cid=wl_hotmailnews _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member