I had been putting in a BB-sized amount of KH2PO4. I didn't this week. I will be doing a major water change on Friday; maybe I'll dump in a bunch and see what happens. I have a "dry-tab" PO4 kit but I don't use it because the dry-tab doesn;t seem to dissolve. _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp.