Chlorine Lock ????

[CarlD]

Yeah, I agree--one 5 gallon jug--same as I recommended before. But you'll probably need to do it twice a day and test the water each time.

Don't add anything else. From now on stick to liquid chlorine. The 12.5% stuff you got from the pool store is basically double-strength ultra bleach--one gallon is like 2 gallons of Ultra Bleach 6%. I am actually finding it more economical to use the 12.5% 5 gallon carboys--it costs me the equivalent of $1.70/gallon of Ultra Bleach--far less than current price bleach.

Your T/A is fine (but Arm&Hammer Baking Soda would have cost you 1/3 and is IDENTICAL to what you used).

Your CYA is a tad high, but all you have to do is shock at 20ppm and (when it's finally clear) maintain in the 5 to 10ppm range. Keep it there and you should find you use less chlorine.

[poolrescue30]

Thanks for your Response CarlD,
I do not have my FAS-DPD test kit yet.Should I shock it with one 5 gal. jug tonight and restest in the pool store tomorrow ? or wait till the kit comes and test it 2 hours after the Liquid Chlorine goes in ??

[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