Thanks Pat, Poolsean, and Richard. I think I've got the algae licked. The FC fell from only 17.5 from 20 FC last night, no algae is visible, the "bubble colonies" clinging to the sides are gone. and the pool is crystal clear. I am running the SWG 2 more hours each day to see if that helps. My goal is 5 FC. My question is, how can people get by with a FC level of 3.5 when the CYA chart says to run it a 5 FC level minimum? Dorie