I think the trick was letting the water get below 60 before closing and opening it before it got above 60. Well that and not using a closing kit full of junk.
Just a little algae around the water line ..vacuumed the bottom to waste...shocked to 12ppm using calhypo. PH was 7.2 raised to 7.8 / CYA 30 ish./ TA 70 raised to 90. Could see the bottom by Saturday night.
Turned the Raypak Versa 255 on last night at 6pm and it was 78 this morning 82 by mid afternoon. Notice the safety cover marks on the deck