Last August we bought a house in the Boston area with a 25'x50' (approx 50k gallons) painted concrete pool built in 2001. The pump/motor were shot, the plumbing at the shed was terrible, the sand filter had never been serviced and I was losing a ton of water. We replumbed, got a new Hayward Ecostar pump, changed the sand in the filter, converted to SWCG (2x Hayward Aquarite with T-cell-15) and replace all the o-rings and gaskets. The water was a fresh fill from my well.
The pool guy came Saturday morning to finish up (replaced the multiport gasket and filter top o-ring and top off the salt - it was at 1300ppm). He tested the water before adding any chems and I had:
I watched him slam 16lbs of CYA into a skimmer line, add another 480lbs of salt, and (I think) 8lbs of what I assumed was 68% cal-hypo. When he swept the shock it bloomed into big clouds of white. When I tested the water with my TF-100 kit Sunday morning the OTO chlorine was almost orange. DPD pegged FC at 17!
Rechecked this morning and FC was still way up there. Leslie's pools just corroborated and said most of the other readings were suspect with that much chlorine.
So what the heck happened to push my chlorine that high? Was it just the shock or is something else going on? With CYA at 45, and possibly more sitting in the filter dissolving, how fast can I expect the chlorine to drop to usable levels? Should I go ahead and drain a bit and refill?