chlorine lockup

[poolmom]

All other chemical levels in pool are normal but pool won't hold chlorine (the water in the pool, which is 17,000 gallons, is only a year old, as this happened last year and was resolved after complete draining and refilling). Chemical levels were normal at closing in September but has not held chlorine since May opening. Best result was a recent shock that when tested next morning had normal chlorine level, then 3 hours later was retested and free chlorine was again zero! Any suggestions to resolve, without draining and refilling again. Thanks!

[Guest]

Many people forget to check their stabalizer level. Not sure what kind of climate you live in but if you get any evaporation, you will lose stabalizer with that. Also, check the date of your filter (if its a cartridge filter) if its not, make sure you've done you backwash. Be sure you dont have too much chlorine, if you do, it can bleach out your reading making it look like you have no chlorine. I would certainly NOT drain it because of this.

[Nick808]

Take a sample to pool store and they will test for free , it does sound like it needs stabalizer..