My last good boil was Sunday 4-13. After Monday with temps 70+ I dumped all the sap, with a nice freeze Wed. and Thur. I tried boiling Friday afternoon with 750 gals, ran it through the RO to 18%. When I stated the evap. that's when it all went to #*^! I don't think all the de-foamer in the world would knock down the crap in the back pan. The plus was I had all the water I needed to clean for the end of the season! First boil was 3-30 and the last should have ben 4-13. We are at 80% only down 20% from last year, It was a hell of a ride for two weeks.