Chlorine and Stabilizer


Well-known member
Jul 11, 2010
I just got my pool filled yesterday (had to drain and refill). I looked over the beginners guide pool-school/temporary_pool_guide. I did not put any bleach in, but last night I started on the shock. According to the guide, 5 oz / 500 gal, I need appox 10 oz (appx 5000 gal). I will keep adding the 10 oz of shock a night for the next 3 nights. My question is, should I go ahead and add the bleach as well? I checked the TC level earlier, it appears to be above 4 (max of tester),thus why I'm questioning adding the bleach. pH is 7.2



Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
Houston, Texas
HTH Shock and Swim is calcium hypochlorite and does not contain stabilizer (CYA). It will raise your FC (free chlorine) but it will also raise your CH (calcium). You do not want calcium to get too high as it will cause cloudy water over time. When your FC drops you can use bleach to raise it back to the recommended level.

Have you put any stabilizer in your pool yet?


LifeTime Supporter
Jan 11, 2009
Cupertino, CA
The temporary pool guide wants you to use dichlor (something whose main or only ingredient is sodium dichloro-s-triazinetrione) not cal-hypo (full name calcium hypochlorite).

At 5 oz per 500 gallons you want 50 oz or round that to 3 lb (48 oz) of dichlor if it comes in 1-lb containers.

This stuff IS your chlorine source while you are adding it, you do not use bleach until you've used up your allotment of dichlor.