With CYA between 60 and 85 PPM intense sun seems to destroy all sodium hypo and calcium-hypo in my pool. It will go from 4 PPM FC and 0.2 PPM CC at 8pm the night before, I'll add 2 PPM 6% sodium-hypo and the next afternoon 0 FC! My sanitizer demand is 1-2 PPM every 24 hours until the outside temperate exceeds 92 degrees. Once the temperature exceeds 92 degrees there is no amount of unprotected chlorine that can survive an entire day time period. It is as-if it is not mixing with the CYA already in the water. Only tri-chlor can maintain a residual. The amazing part is my pool is positioned to only be in direct sunlight a few hours each day.
Is there any known way to keep a residual all day without a combined sanitizer-stabilizer like tri-chlor?
Viking Gulf Shores fiberglass IG (19,000 ga) with painted concrete patio.
A small fortune in Taylor Tech testing equipment.
LSI Index: As close to zero as I can get it.
FC, CC, CYA see above.
TDS about 1,100 at mid-May startup.
Pool store says no copper or iron in water. No stains observed.
Filter: Hayward 72 ft^2 DE
Pump: Hayward 1.5 HP Superpump.
1 skimmer, 3 shallow returns, 1 deep return. 1 slide.
Water is extremely clear, but I know algae is not far away with 0 FC.
Thanks in advance!
St. Louis, Missouri