dichlor "shock" bags CYA content


LifeTime Supporter
Apr 26, 2008
Southern New Mexico
I have been using bleach to get my FC up to 6 (cya about 60-70) but am struggling to get it there. Using over a gallon of bleach daily, which seems a little too much. I want to get the FC up high and see what the daily liquid chlorine use is once its "up there." The pool shop guy told my the pucks of di and trichlor have the CYA in them , but not the shock bags...Does anyone know if that is true? Can one use dichlor granules without fear of getting into CYA overdose? Muchas Gracias..


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida

You didn't ask, I know, but just a comment on your chlorine.

I agree that a gallon a day is just a little high at that CYA level. 3.3ppm daily Cl loss in your pool.

Test your chlorine in the evening and then test it again early in the morning before the sun gets on the pool. If you've lost more than 1.0ppm of Cl overnite, you have algae and need to shock your pool. That'll slow down that chlorine loss and let you bring your FC up to where you want it.