Kathy, I use Bicarb Soda in all my tanks. I mainly use it to help buffer water and to help with maintaining the PH. I have not had a problem with ph dropping or anything but I think that has a lot to do with filtration in general. I use one tea spoon / 10 gals and have found it to work quite well for us in the last two years. I also use Salt as well in the tank to keep the GH up. Epsom's work well. I don't filter with carbon on much of anything except the eclipse which the Endlers are housed in and my Quarantine tank. I have used crushed coral substrate but it eventually started to break down and started to soften my water. this was before I used Bicarb soda. I have had some strange experiences however and by no means see this as a normal event unless someone else can say that they had similar happen to them? I do frequent water changes weekly basis, about 10 to 20 % in all my tanks. when I do them I always add bicarb soda. Hopefully that will be helpful? Paul -----Original Message----- From: owner-gsas-board@thekrib.com [mailto:owner-gsas-board@thekrib.com]On Behalf Of Kathy Olson Sent: Wednesday, October 10, 2001 9:15 AM To: gsas-board@thekrib.com Subject: Endler's livebearers Paul, We had to leave pretty quick last night, but I wanted to hear how you harden the water for your Endler's livebearers. I heard about adding Sodium Bicarbonate but not the ratio. I thought it would be good for everyone (myself included) to hear an alternative way to harden the water. Thanks Kathy