Chlorine Lock ????

[poolrescue30]

I have a 33k gallon vinyl lined pool.had ahell ofa time getting the water clean upon start up 3 weeks ago.I did have a LOT of leaves in the deep end after the pool guys removed the cover and let it all go in the pool .My combined chlorine is steady at 4.6 ppm and free chlorine is .6 ppm. The pool store is tellimg me I have "chlorine lock" due to organic materials that were in the pool.
The water finally got clear and is even sparkling .the kids went in over the weekend and did not complain of any irritation.How do I get rid of the chlorine lock ??
THANKS

[JohnT]

What is your CYA level?

[Watermom]

I think you must have your chlorine numbers listed backwards. Your FC must be 4.6 and your CC must be 0.6. Post a full set of current water testing results taken with a drops-based kit, including cya as JohnT suggested, and somebody here can take a look. Also, tell us exactly what all you have added to your pool --- not just "shock", but ingredients.

[poolrescue30]

My Numbers:

Alkalinity 160

pH 7.2

CYA 40

Hardness 220

Total Chlorine 4.6

Free Chlorine 0

[Watermom]

Your numbers are fine. With a cya of 40, just keep your chlorine between 3-6 all the time. When you let it dip below 3 is when you risk starting an algae bloom. Watch your ph. Anywhere between 7.2-7.8 is good. Below 7.0 is acidic and can damage your pool. Your alk is a little high, but shouldn't cause any problems. Ignore what the pool store says about chlorine lock. If your numbers are good like yours are, and the water is sparkling, go swim and enjoy your pool. Hope this helps.

BTW FC + CC = TC always.

[waterbear]

My Numbers:


Total Chlorine 4.6

Free Chlorine 0

If this is correct it means that you have NO free chlorine and all the chlorine in your pool is combined chlorine. This indicates a very high organic load or high ammonia levels in your water.
Did your CYA level drop over the winter? Was any kind of algaecide or teatement added to the pool at openening such as Yellow Treat? (a powder that requires shocking afterward to kill algae and 'clean' the water).
You might want to test the ammonia and nitrate levels in your water (most pool stores don't test for these. Use an aquarium test kit to test them).

[Watermom]

Evan,
I assumed it was simply a testing/reporting error on poolrescue30's part. I assumed he meant FC 4.6 and CC 0.6. If you read back to his first post, at that point he said CC 4.6. So, I just assumed reporting error on his part rather than a significant problem.

[waterbear]

Evan,
I assumed it was simply a testing/reporting error on poolrescue30's part. I assumed he meant FC 4.6 and CC 0.6. If you read back to his first post, at that point he said CC 4.6. So, I just assumed reporting error on his part rather than a significant problem.

He also reported an initial FC of .6 and that the pool store told him that a high organic level was 'locking' the chlorine. We both know that chlorine lock is a myth BUT a high organic level can and will make it next to impossible to hold FC and cal lead to very high CC levels, particularly if there is ammonia in the water. We also know that CYA can degrade in closed pool and be broken down into ammonia compounds. If there was an overdose of ammonia based algae treatments (Yellow Treat, etc.) used this could also explain the problem.
The cure for this is shocking to very high FC levels but this is problematic in a vinyl pool. The other alternative is to dilute (drain and refill) so normal shocking can handle the ammonia and chloriamine levels.

[poolrescue30]

Thank for all your replies , my numbers stated were corect :

Total Chlorine 4.6

Free Chlorine 0

The pool store guy said to dump 2 gallons of amonnia in to break up the organics ???? but according to your replies it sounds like high ammonia is the problem !!! Do I need to drop the water level ?? if so how much ??/ THANKS

[mas985]

Sounds like you need to shock the pool. 8 gallons of 6% bleach should do.