High CYA, q about Chlorine level

[daleyfolk]

I am awaiting my TF-100 kit. In the meantime, my test strip indicates that I have CYA of approx. 100.
Assuming this is in the ballpark, I should keep my FCC level about 7.

I understand that I can maintain my pool w the high CYA, (while I await my new science kit). it's just gonna cost me more in bleach.

My question is if I maintain FC of 7 or 8 to keep algae at bay, is this twice as potent on swim suits, equipment, etc as a pool with lower CYA and FC in the "normal" range (3.) Or Does my high CYA "neutralize" some percentage of the FC? (I'm nervous about keeping my FC so high.)

20k vinyl pool looks great. I did find some green algae three days ago on the step seams and the skimmer insert seams. Brushed it all off.

 

[JasonLion]

Welcome to TFP!

Test strip CYA tests are exceptionally unreliable. Your CYA level could just as likely be just about anything.

If CYA is really 100, you should replace water to get CYA down to something more reasonable. At high CYA levels you will have a variety of problems, though using more chlorine is not one of them.

CYA holds some of the chlorine "in reserve" so that it has no effect. We recommend higher FC levels to bring the active chlorine level back up to the same level it was at lower FC with lower CYA.

 

[daleyfolk]

Thank you for the reply. Am anxious to get the real CYA story when my test kit arrives.

 

[timerguy]

If your strips are anywhere close to being accurate (doubtful), for your first cya test with your new kit, you might want to do a diluted sample using the following instructions:

If your CYA level is 90 or higher, repeat the test adjusting the procedure as follows:Fill the mixing bottle to the lower mark with pool water.Continue filling the mixing bottle to the upper mark with tap water.Shake briefly to mix.Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark.Continue the test normally from step 3, but multiply the final result by two.

That just might save some r-0013 reagent. If your cya is much higher, say 200 or more-- that can happen, you may have to dilute it more than once. Good luck!
http://www.troublefreepool.com/threads/24188-Extended-Test-Kit-Directions