We started this pool season with a green swamp. Found this forum & realized our CYA was well over 150. Have been using the "Best Guess" chart, drained some water, raised chlorine to "shock" levels appropriate to our CYA, etc. We use Taylor's FAS/DPD kit.
Anyway, our pool LOOKS beautiful. However, we have NEVER had a CC reading of zero. When we test the CC, the water always turns a very light pink. It takes one drop of solution to then make the water clear...therefore giving us a reading of approximately .5 CC.
So, for the last six nights, we've tested the chlorine & gotten FC levels ranging from 18 to 20 ppm. Each night the CC's have been at .5 ppm. Each night we've added chlorine to bring the FC to at least 20 ppm. Should we start testing each morning also? If the FC is below 20 should we add more chlorine immediately in the morning? Between the sun, heat & CC reading we are losing 5ppm each day. Here's tonight's numbers:
This is driving us crazy!! We have added more than 8 gallons of 15% chlorine in the last six days. (To save you time doing the math: 1 gallon adds 5ppm to our pool.)* We have kept the filter on 24/7 for around two weeks now. Should we just keep at this, knowing that eventually all of the chlorimates will be gone & we'll be able to let our FC drift down to 5-10ppm?
Is it okay for the kids to swim in FC levels between 15 and 25?
We have: 30,000* gal, vinyl IG with sand filter. We live in Milwaukee, WI area.