Hi all,
Opened our pool last weekend & found very green walls & floor, but fairly clear 54 degree water. Usually when I close I throw in the floater with chlorine pucks, but last fall I tried Polyquat instead. Maybe a bad move... in the past I've never had much algae on opening.
Anyway, I got the pump fired up, walls & floor brushed, and began SLAM with 10% Walmart bleach. My CYA was/is about 50, and I figured I shouldn't bring it up to SWG level until the SLAM is done. So the Pool Calculator says with CYA at 50, shock level should be 16. However the Pool School Chlorine/CYA Chart shows a shock of 20 for CYA of 50 (non-SWG; the SWG chart doesn't go down to 50).
My question is - should I be trusting the Pool Calculator shock of 16 for my circumstances? Or do I need to go higher?
The pool is looking really good, and I did pass OCLT Thursday morning but ran SLAM one more day for good measure and failed it this morning... So that made me question my process a bit.
Any thoughts appreciated... Thanks!
Opened our pool last weekend & found very green walls & floor, but fairly clear 54 degree water. Usually when I close I throw in the floater with chlorine pucks, but last fall I tried Polyquat instead. Maybe a bad move... in the past I've never had much algae on opening.
Anyway, I got the pump fired up, walls & floor brushed, and began SLAM with 10% Walmart bleach. My CYA was/is about 50, and I figured I shouldn't bring it up to SWG level until the SLAM is done. So the Pool Calculator says with CYA at 50, shock level should be 16. However the Pool School Chlorine/CYA Chart shows a shock of 20 for CYA of 50 (non-SWG; the SWG chart doesn't go down to 50).
My question is - should I be trusting the Pool Calculator shock of 16 for my circumstances? Or do I need to go higher?
The pool is looking really good, and I did pass OCLT Thursday morning but ran SLAM one more day for good measure and failed it this morning... So that made me question my process a bit.
Any thoughts appreciated... Thanks!