CYA Zero

[cardopa1]

Hi

I have an inground vinyl pool and just replaced the liner a few weeks ago and of course filled the pool with new water. My PH has been 7.8, my free chlorine 3 - 5 and my TA 150. However I can't get a reading on CYA - it has been zero. Is that a problem ? Will it eventually rise ?

 

[pwrstrk]

Hi

I have an inground vinyl pool and just replaced the liner a few weeks ago and of course filled the pool with new water. My PH has been 7.8, my free chlorine 3 - 5 and my TA 150. However I can't get a reading on CYA - it has been zero. Is that a problem ? Will it eventually rise ?

That depends what your chlorine source is. Are you using pucks ? If your using liquid chlorine, bleach, it won't rise because it doesn't add CYA like the pucks do. If your using liquid chlorine you need to manually add CYA.
The CYA is what protects your chlorine from the sun. With zero chlorine you'll lose almost all your chlorine due to burn off from the sun.
PH at 7.8 you should lower that a bit with acid.

 

[cardopa1]

For the first week I used bleach. For the last week and a half I have been using pucks. My chlorine level has been consistent.

 

[Richard320]

You're in good shape, then! If you can figure out how many 8 oz pucks you've used, you can get a close approximation of how much CYA you've added so far and use that as your NOW reading. Then it's just a matter of using pucks until CYA is where you want, or adding stabilizer alone and switching to bleach.

Effects of Adding Chemicals at the bottom of Poolmath will tell you how much each puck adds, after you plug in your pool volume. 20 lbs of pucks will raise CYA to about 50 in your pool by the time they're all used up.

 

[jblizzle]

How are you testing?
The pucks are adding CYA, but it may take awhile to reach a level you can test for. In the meantime, you are loosing a LOT of chlorine to the sun.

I would suggest adding about 20ppm of stabilizer and then tracking your tablet usage and use PoolMath to tell you how much CYA you are adding with them and then stop using pucks when you get in the 30-50ppm CYA range.