Thanks. I gradually brought the Alk up to 80. Last evening FC was 5.5, CC still 0.5, so I put in 2.5 gallons of 6% bleach. That brought my FC up to 13 (I'm wondering if my pool really is 26000 gallons after all). I left the pump running with the SWG off. This morning FC was still at to 12 so I kept the SWG off. Now FC is 10.5, CC is 0. I guess whatever was causing the .5 CC is killed off now! I'll keep the SWG off until FC gets back down to around 4. I'll check the SWG section for Cya and Cal related discussions.

Thanks for your help.
-Steve