How to read CYA

[New2PoolsInAZ]

I apologize if this has been posted already. When I do CYA testing with my Taylor K-2006 do I fill the test tube until the black dot completely disappears or just until I cannot see it with much effort. It totally disappears for me at 50 (same with a cheaper test kit I have), but it's almost impossible to see around 65. I do the test under my kitchen light.

 

[frogabog]

Disappears means the same as impossible to see. I'd go with 60-65. I would not round up to 70 at your "impossible to see", but assuming 65 if it's really 60 won't make or break you while in maintenance mode.

You may consider some draining and adding water to get that down a little bit though. Backwashing and vacuuming to waste and refilling is a productive method to lower CYA.

 

[ajw22]

Disappears means the same as impossible to see. I'd go with 60-65. I would not round up to 70 at your "impossible to see", but assuming 65 if it's really 60 won't make or break you while in maintenance mode.

You can’t measure CYA 65. The scale between lines is logarithmic, not linear. Halfway between lines is not 5. You cant judge what it is.

Always round up to then use the FC/CYA Levels. You cant go wrong calling your CYA a bit high.

 

[New2PoolsInAZ]

Thank you very much. I will do as you say and also have my wife check next time too, she has better eyes than I.

The pool was at over 100 CYA and (just starting with TFP) switched from Trichlor to liquid chlorine and spent the last couple of days draining and filling the pool at the same time so as to not damage it, until CYA was at 50. I had to buy a pump to do this as my filter does not allow me to backwash.

 

[ajw22]

Black dot just disappears...

 

[setsailsoon]

New2,

Welcome! Most people have a little difficulty with this one but with experience it will get easier. Do the test outside with your back to the sun. Don't stare at the dot. Look up and then down to do the test. If you don't see the dot right away it's gone. As Allen suggests always round up. If you have problems watch the Taylor video or you can get a standard solution of 50 ppm to gauge your technique.

Hope this helps.

Chris

 

[ajw22]

You can pour the solution back into the mixing bottle and do the test multiple times. Don’t second guess yourself just stop when dot just disappears. Dont stare at the dot after. Do it 3X and average the results until you get confident.

 

[AimeeH]

As setsailsoon said.......do the test outside in full sun with back to the sun holding view vial about waist level

 

[New2PoolsInAZ]

Thanks, everyone. I will do the test as setsailsoon said. I may have my wife check the result too.