Chlorine Lock ????

[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.

[poolrescue30]

I've shocked already 3 times with Non-chlorine shock , and 3 times with chlorine shock. Is the bleach better than 'store" shock ?? how do I find the percentages onf the bleach ??

THANKS !!!

[poolrescue30]

Ok,
I'm going to shock today with 8 gallons of the Walmart Ultra bleach.Do I pour it around the pool or into the skimmers? I have a vinyl liner and don't want to bleach it .How will I know if I hit 20ppm ?? When should I add more bleach to "keep it" at 20ppm ??

[waterbear]

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

Pool store guy missed the mark. Adding anhydrous ammonia to a pool with algae and then shocking will produce monochloramine which will quickly kill the algae http://www.poolsolutions.com/tips/tip08.html but it creates a hugh chlorine demand and you will have NO FC and all CC. http://www.poolsolutions.com/tips/tip40.html

It is NOT what you want to do when you already have a situation where you have all CC and no FC. My suggestion is to test for ammonia using an aquarium test kit. If you have a lot of ammonia in the water then all you can do is either drain and refill to dilute it and then shock or shock repeatedly with bleach. Non chlorine shock is not that effective against ammonia and CC that have already formed. Shocking with chorine and UV from sunlight are.