Oh, by the way....fire your pool guy. Tossing granular chlorine in the pool is a bad idea...as you can damage the bottom if it sits there too long. One time, a long time ago....some guy tossed 15 bags of Stabilized Super Shock in my pool, the idiot took my CYA up to 150. And he wanted to charge me $20/bag....really???!!!....I always pre-dissolve calcium, CYA, and 73 Cal Hypo in 5 gal buckets. I have had nothing but bad experiences with these "pool" people and now that we are on the TFT method using the TFT-100, all is well. I notice you are in N VA, I am in S MD. So we have similar environments...thus I strongly suggest that you SLAM the pool every year within 2-3 days after you open it after getting it balanced.....get an SWG and you are on auto-pilot. I bought a Nautilus CC Robot and now my pool is always clean (lots of trees) and almost maintenance-free, other than adding acid for pH. Love it.