CYA adjustment before salt addition

[PNWDad]

Preparing to add NaCl this weekend. Have the TFP Kit, CYA is over 100, If I dilute current pool water by 50% then it goes to approx 60. Currently dumping water. The pool was previously chlorinated with tablets. Question, how did CYA build-up so high in the pool? Did years of tablet use and stabilizer addition create this scenario, or does it happen by some other mechanism? Tempted to drop the pool volume to around 40% prior to refill to allow for a target CYA of about 50? Thoughts?

Thank you...

 

[Texas Splash]

how did CYA build-up so high in the pool? Did years of tablet use and stabilizer addition create this scenario,

Exactly! Misuse of tablets and bags of shock.

Tempted to drop the pool volume to around 40% prior to refill to allow for a target CYA of about 50? Thoughts?

Actually, shoot for a CYA target of 70. That's the minimum you want for a SWG pool so that you have adequate FC protection from the sun.

 

[PNWDad]

Ok, thanks, thought so, but also did not know if it was a by-product of anything used in the TFP method. I'm aiming a bit low because I'm in the PNW where there is not a tremendous amount of sun, and because it is easier to raise, than lower. Is CYA a skin/eye irritant?

One other Q, should I add salt, then adjust PH after the re-fill or adjust PH then add salt?

 

[domct203]

High CYA is the result of using stabilized chlorine (trichlor/dichlor).

TFP recommends using liquid chlorine, which adds only chlorine and a trace amount of salt.

CYA, in the levels recommended here, is not an irritant.

Get your water well balanced first, then add your salt.

Dom