Chlorine Lock ????

[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 !!!

[mas985]

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 !!!

Skip the non-chlorine shock. I don't think really does much but bleach is a much cheaper way to shock the pool and it won't add anything that you really don't need anyway. Bleach is a very effective way to remove the combined chlorine. Walmart is about the cheapest you will find 6% bleach, just make sure it is the plain version without additives.

You will need 8 gallons to bring the pool up to shock level and maybe more to keep it there for a day or so. So you might want to get a little bit more. You might also be fighting some algae which might require you to keep the pool at shock level for more than a day to ensure a good kill. Part of the problem maybe that you did not use enough chlorine for a good shock so that is why you need to start with 8 gallons. It seems like a lot but it will cost less in the long run to get things back to normal.

[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]

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 ??
By testing your water. You DO have a good testkit with the FAS-DPD chlorine test, don't you? It's a BASIC piece of pool equipment!
When should I add more bleach to "keep it" at 20ppm ??
When your testing has shown that the level has dropped below 20 ppm.

Hope this helps. You really need a good test kit, Many people don't get one until they run into a problem like yours. If you has been testing your own water all along... you get the idea.

[poolrescue30]

HI,
I dumped in the 8 gallons of 6% Bleach on Tuesday morning , then had to leave town on an emergency for work so I only got back tonight .I do not have the FAS-DPD chlorine test kit and will get one, however the pool water looks much clearer now , pool test kit shows 2-3 ppm chlorine, Alkalinity of 100, and pH of 6.8, so I added a little pH rise and we"ll see tomorrow eveneing how it is .I think we might have cleared up some of the CC problem.
Can anyone tell me where to get a FAS-DPD chlorine test that goes up to 20ppm?
thanks

[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.