Chlorine Lock ????

[aylad]

You can test it 2 hours after the liquid chlorine comes in, since to clear this up you're going to need to sustain your 20 ppm reading--it'll probably be time to add more, anyway.

You need to get the tabs out of the chlorinator, or at least turn it off. As your CYA gets higher, so does your baseline and shock values for chlorine required to keep your pool clear....and if you're already having problems getting it clear, the last thing you want to do is increase your chlorine demand a little more.

Janet

[CarlD]

Thanks, Jan!

Do a seach on "Shot Glass Method" which allows you to use an OTO test kit to get an approximation for higher FC levels than are on the scale.

You may also want to search on OTO colors above 5ppm--Ben had done some work on colors for much higher OTO levels.

Meanwhile, over at TFP, they are debating some of that and there's an easy-to-find discussion with the color scales that Ben had done. Maybe we can get some cross-pollination....

[poolrescue30]

I guess I forgot to update you all properly.the algae is all gone, none visibly left in the pool.the water is perfectly clear and you can see the seams in the liner at 10 feet deep. So i really don't know what's eating the chlorine.I will test the water again tomorrow, and try to maintain 5-10 ppm but can the kids swim in such high chlorine ??

[CarlD]

Remember:

Algae itself isn't dangerous--you can swim in lakes, rivers and ponds with algae. But algae forces your chlorine to be consumed fighting it, leaving you no chlorine to fight the bad biologics--water-borne diseases and bacteria. It strips your pool of its defenses against the serious stuff. That's why you have to get your CC to <.5 and your FC to hold and not drop precipitously.

You can swim in higher chlorine levels (relative to your CYA level) just wear older bathing suits so if they fade it's OK.

[poolrescue30]

I went to the pool store this morning at 9:30 am, I had shocked the pool yesterday at 4:00pm with the 5 gallon jug of 12.5 Liquid Chlorine.This morning's numbers were :

FCL 0 !!!!!

TCL 1.7

CC 1.7


pH 7.8

ALK 99

CYA 70

There is no visible algae in the pool , pool is crystal clear , what in the world is using up the chlorine ?? the skimmer bakets were cleaned , filter backwashed , before I shocked and 15 hours later , NO CHLORINE ??? Of course the pool store did a phosphate test , but that too came out negative .
Pool store suggested I shock tonight with TWO 5 gallong jugs of 12.5 , is that gonna do it ???
I need help !!!!!!!!!!

[CarlD]

No. It's better to shock tonight with one carboy and then again in the morning.

BUT YOU MUST KEEP UP A CONSISTENT LEVEL OF CHLORINE OR YOU WILL NEVER SOLVE YOUR PROBLEM! AND ALGAE IS NOT YOUR PROBLEM--YOU HAVE ANOTHER BIOLOGIC YOU MUST KILL!

You MUST check and adjust your chlorine 3x a day now. You have no alternative--2x a day isn't enough. 1st thing in the morning, late afternoon or before dinner, and at bed time.

Use the dilution method with your OTO set if you must. Use test strips if you must--you can tell with them if FC is above 10ppm or below it. You MUST hammer your pool with chlorine--putting in two carboys at once may well damage your liner--better to get your pool to shock level and keep it there, seperating them by 8-12 hours.

[chem geek]

waterbear gave you some advice in this post regarding the possibility of ammonia and getting an inexpensive ammonia test kit from a pet/fish/aquarium store. I suggest you get such a kit since it will tell you if you have ammonia in the water. Ammonia can be formed in a pool over the winter when a pool is "let go" (not maintained with chlorine) as bacteria can convert CYA into ammonia.

If you have ammonia in the water, then it takes a cumulative FC of around 10x that ammonia amount to get rid of it. So this can give you a rough idea of how much more chlorine it will take -- if there is ammonia in the water.

Or you can just keep adding chlorine and eventually it will hold, but you won't know how much more it will take.

Also, in this post on June 23rd you reported a TA of 160 while in this post on July 3rd you reported a TA of 16 from your LaMotte test kit (did you mean 16 drops which is 160 ppm TA?) and this post on July 6th where your pool store reports 0 ppm TA after which you added Alkalinity Up. I doubt very much that your TA went away that quickly.

Richard

[poolrescue30]

Chem geek,
I have followed everyone's advice here EXACTLY .I did test for ammonia and it was negative . I gave all the right TA numbers here, it looks like somehow the ALK did nosedive, first it was 160 , then when I said 16, that's what it was 16 , down from 160, then a couple of days later is was 0, we had alot of rain here and I did let out about 3K gallons twice during that period trying to get rid of the CC.
I did dump in 3 gallons of ammonia on the advice of the new pool guy, but I can't imagine the amount of 6% bleach and 12.5% LC was not enough to get rid of that amount .My big question is , is dumping the chlorine in slowly getting the organics I'm trying to kill even if I can't maintain it at a constant level due to work hours ? or am I wasting my time??

THANKS FOR EVERYONE'S HELP AND ADVICE !!!

[chem geek]

I didn't mean to be accusatory...I just saw some things that seemed inconsistent or strange. I'm glad you're hanging in there. As for what to do about the organics or whatever the chlorine demand is coming from, the answer is it depends. If the organics are static such as a fixed amount of pollen, ammonia (which you say you don't have), lotion, etc., then it's the cumulative chlorine amount that gets rid of it. If the organics are living and reproducing such as algae, then if the chlorine level gets low and isn't maintained at or near shock level, then the chlorine demand won't go away. If you don't know what it is, then play it safe and try (as best you can) to keep the chlorine level up as much as possible.

With the TA measurement of 16, was this a pool store measurement? The standard TA test kits have one drop for every 10 ppm so you can't really get 16 ppm with your own test.

Richard