Quote Originally Posted by gldungan
The pink disappears around 2.8 but the water is cloudy.

CL 2.8
CC 0
pH 7.6
Alk 90
Cal 330
cya 55
Gunite pool with SWG 18,000 gallons, 85 F

Any thoughts would be greatly appreciated.

Gary
Gary,
Your chemicals are FINE: If you check the Best Guess table you will see that for a CYA over 55 you should maintain a MINIMUM FC of 5ppm--that's probably your problem. 55 is a funny number--I assume it was halfway between 50 and 60--that's actually higher--like 58 or so--and figuring 60 is safe.

Best guess says if your CYA is 30 to 50, your FC must be 3 to 6 and shock to 15ppm. If your CYA is 60 to 90 then your FC must be 5 to 10 and shock to 20ppm.
I tend to keep my FC at the same end as my CYA (30 implies FC of 3 or 4, 50 implies 5 or 6). It's not exact--it's a BEST GUESS.

Conditions over the years can change in your water, especially if you haven't had a kit like the PS-23x series, you wouldn't realize it.

My suggestion, to start, is that you shock your pool. Shock it to between 15 and 20--and keep it there until the water clears. Run the pump 24/7 during this. Then let FC drop to the 5 to 10 range. If THIS doesn't work then we can go to plan B.

You only need enough DPD powder to turn the water nicely pink. Any more just wastes the powder--it doesn't turn it pinker. It seems weird, but that's how the stuff works. For the higher FC ranges, just use the 10ml test--you'll save reagent and being within .5 on your FC is enough. Actually, it's usually enough all the time!