Confused about CYA

[circlenranch]

"The CYA keeps the sun from consuming it all, but it also makes the Cl less aggressive toward "goo" in your pool, requiring more of the Cl to do the same job."

Ah, now I understand. Thanks aylad!

[karrde97]

I had the same confusion. My pool is in sunlight all day and I'm putting in 2-3 Quarts a night(On sunny days. Nothing on cloudy/rainy days). My CYA=40. Now it makes sense.

A question I have is that the Best Guess Chart is based on FC. Does this mean I have to test my FC every day? I don't have enough powder(PS234) to do this all summer. I will have to buy more. I've been using the PS200 to check for CL & pH daily.

[JohnT]

A question I have is that the Best Guess Chart is based on FC. Does this mean I have to test my FC every day? I don't have enough powder(PS234) to do this all summer. I will have to buy more. I've been using the PS200 to check for CL & pH daily.

It is intended that you do the daily check with the PS200. I only use the powder on Saturdays and if I have reason to suspect a problem.

[aylad]

It's a good idea to check it daily until you get a feel for your pool--I can pretty much predict what mine's going to be from day to day based on my average daily chlorine loss.

Janet

[karrde97]

The trend I'm starting to notice is that on sunny days I need to add 2-3 quarts. Rainy/cloudy days 0-1quart.

Another question...Has somebody done a cost comparison of bleach versus chlorine? I'm curious since I'm putting so much bleach in per week.

[JohnT]

Has somebody done a cost comparison of bleach versus chlorine? I'm curious since I'm putting so much bleach in per week.

Bleach IS chlorine, specifically sodium hypochlorite. Cost isn't the issue. Bleach, either as laundry bleach or the stuff you buy at the poolstore in higher concentration is the only thing that doesn't add something that will cause you trouble a few seasons down the road. Trichlor and dichlor add CYA. Cal-hypo adds calcium.