Current measurements--Questions about CYA and TA


Well-known member
Jul 19, 2011
Lehigh Valley, PA
Added a pound of shock last night to raise the FC and the CYA

Pool looks pretty darn blue.
Two questions. I have the TF-100 kit.
1) When you do the CYA test are you supposed to wait till you totally cant see the black dot at all ?
2) For the TA test, I know it says to add drops until it becomes RED--but mine just turns a dark pink no matter how many drops I add. Is this correct ?


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
1) Correct, totally not at all there even if you stare at it for a few seconds.
2) Anything in the red/pink family will do. Add drops till it start to turn red/pink. Then keep adding drops as long as the color continues to change. The final drop, which does not change the color any further, does not count.