Getting ready to do a partial drain and refill of my pool to address elevated CYA levels inherited from prior homeowner.
When I did previous CYA testing myself a few weeks ago (Taylor kit), light conditions weren't right (didn't know then).
Just repeated test on a very sunny day here in FL - sunshine at my back, test vial in the shadow of my own body and held at waist level. Concrete on pool deck is very light, almost white, but vial was held in a way where there was shade underneath - no direct sun.
Since I knew the value was going to be high, and to be sure I had good resolution on the test, here's how I prepared the sample:
Mix 10 mL pool water and 20 mL distilled water in a small glass (all measured with graduated syringe) - stir well.
Take 7 mL of the mixed sample and put it in the CYA mixing bottle.
Add 7 mL of CYA test reagent as usual.
Perform test and multiply result by 3 to account for 1 part pool water and 2 parts distilled water used in test.
When actually filling the black dot vial, near the endpoint, I would temporarily lose sight of the dot, but if I moved my head ever so slightly I would regain "focus" and could barely make it out again, so added a few more drops until it was really and truly "gone". I repeated the fill test about 5 times and got very similar results, ranging from 45 to 50 ppm each time. So actual CYA would be 135-150, call it 145.
Does all this sound about right? Important for me to feel confident here as I am getting ready to drain the pool and I don't want to over- or under-shoot on volume adjustment.
When I did previous CYA testing myself a few weeks ago (Taylor kit), light conditions weren't right (didn't know then).
Just repeated test on a very sunny day here in FL - sunshine at my back, test vial in the shadow of my own body and held at waist level. Concrete on pool deck is very light, almost white, but vial was held in a way where there was shade underneath - no direct sun.
Since I knew the value was going to be high, and to be sure I had good resolution on the test, here's how I prepared the sample:
Mix 10 mL pool water and 20 mL distilled water in a small glass (all measured with graduated syringe) - stir well.
Take 7 mL of the mixed sample and put it in the CYA mixing bottle.
Add 7 mL of CYA test reagent as usual.
Perform test and multiply result by 3 to account for 1 part pool water and 2 parts distilled water used in test.
When actually filling the black dot vial, near the endpoint, I would temporarily lose sight of the dot, but if I moved my head ever so slightly I would regain "focus" and could barely make it out again, so added a few more drops until it was really and truly "gone". I repeated the fill test about 5 times and got very similar results, ranging from 45 to 50 ppm each time. So actual CYA would be 135-150, call it 145.
Does all this sound about right? Important for me to feel confident here as I am getting ready to drain the pool and I don't want to over- or under-shoot on volume adjustment.
