I was testing the pool water today to get base levels.
To set the stage: We have not yet taken off the winter cover, not circulated the water, nor added any chemicals since the fall closing. Ordered and received new FAS/DPD test regents. The water temp is 60 degrees near the surface.
When testing for FC, the water sample stayed clear to slight gray in color after mixing in heaping test spoon of R-0870 DPD powder. Just for kicks I added the R-0003 reagent and the water turned pink after the first drop and remained pink for at least 60 drops till I gave up trying.
I tested FC using the Basic test kit and FC measured 0.5. Just as I figured, basically no chlorine.
I started over with the water sample and DPD powder and same slight gray color. Just for kicks, I added 1 drop of R-0003 to get the color pink and then added drops of R-0871. It took 5 drops to turn clear, meaning 2.5.
I also tried it this time with: water sample, powder, then 5 drops R-0003 reagent and then it only took 1 drop of R-0871 to turn the sample clear.
Obviously something is not right.
I know the FC test results with FAS/DPD will not effect my course of action but I'm just curious what might be happening.
I will be shocking the pool upon opening because the water is clear but slightly green in color and there are dark powdery looking piles on the bottom, which I'm sure are algae since I have seen them before and that's what it was.
Other results for those interested:
pH - 7.2, TA - 30, CH -40, CYA - somewhere btwn 30 and 40, Borates - 0-15, Salts - 660.