Help!! I don't know who to believe - Chlorine Lock?

[btozzo]

Wow, thanks for all the help guys!

Alright, as I said I was going to do, I added 1/2 teaspoon of bleach to a gallon of pool water last night at 7:00. This morning at 5:45 my chlorine reading was a little high in the bucket. I have a cheap kit, and am going to buy a Taylor, but it looks like about higher than 3.0 as my kit tops out at 3.o and it was darker than that.

To answer PoolDocs questions:

2. Never heard of those brands and haven't used anything this year other than algaecide, chlorine and pH UP.
3. I think I may have used some stabilizer last year, but I keep bad records. I remember putting in some stuff that the pool store wanted me to that took a long time to dissolve and sat on the botton of the pool. Maybe that was it? But I didn't do it at the end of the season as far as I can remember.
4. Never heard of Baqua Shock.

So what now everyone? Should I just do the calculations and buy the bleach? My pool is 24000 gallons.

Thanks again!

Bill

[CarlD]

You should still post those test numbers. Then explore our forums on testing, maintenance and algae, for starters. There are threads that are stickied, usually authored by either PoolDoc, Watermom, aylad, Poconos, or me.

Then go to PoolDoc's other site, PoolSolutions.com and read the tips that are there. This shouldn't take long and it's interesting reading (except what I wrote...--J/K )

But those test numbers will give us a baseline of what to recommend.

We almost always keep it simple, because 99.99% of all pool owner problems ARE, ultimately solved with simple solutions and ordinary chemicals, and very few have to be purchased at a pool store or in the pool section of discount houses.

The best part is it works! Like you, I came here years ago with lots of problems, having been "Pool Stored" to the point where my only other option was to drain and refill my pool. The B-B-B method (Bleach, Borax, and Baking Soda) works on the littlest pools (the one with the problems was a 15' Intex donut--3500 gallons) to the biggest (we now have a 20,000 gallon FantaSea). All you do is adjust amounts you use.

[PoolDoc]

Arg-g-gh! 1/2 tsp in 1 gallon?? You're going to make me work hard. I'm used to figuring doses in 10,000 gallons of water or even 120,000 gallons. But working with 1/2 tsp in 1 gallon? Sheesh.

Ok. Better do it here so someone can check my math.

1 US teaspoon = 4.92892159 milliliters
1 US gallon = 3,785.41178 milliliters or 3,875 gm

1/2 tsp = 2.46 ml = 2.46 gm/H20
at 6% bleach that's approximately 0.148 gm Cl2 equiv

so your dose was
(0.148 / 3 875) * 1 000 000 = 38.1935484

or 38 ppm chlorine.

Yep, if my math and your testing is correct, you've got a lot of chlorine demand there.

I'd recommend using 4 gallon (~10ppm) doses in the evening, and continuing till you hold a residual.

Watch your pH during this, and add borax a box at at time, to keep it above 7.6


Have fun!

PoolDoc

[CarlD]

from Chem_Geek's post:

You can take a bucket of pool water and add 6% bleach to it. 1/4 teaspoon of 6% bleach in 2 gallons is 10 ppm Free Chlorine (FC).

So...1/2 teaspoon in 1 gallon is four times the concentration Chem_Geek lays out.....

I prefer to use a glass eyedropper and add 10ml to 10 liters of water (that's 5 2-liter soda bottles). That's the same as figuring based on 10,000 gallons.....

[btozzo]

Alrighty! Will do!

I have a question though. The way I worked the math was with a proportion. If .5 teaspoons effectively chlorinates 1 gallon of pool water, then 12000 teaspoons should effectively chlorinate 24000 gallons. Converting 12000 teaspoons to gallons gives me 15.625 gallons of bleach. Am I correct? So will I be adding 4 gallons a night for about 4 nights?

Also, Walmart didn;t have Borax! I'm going to have the wife look at Target and Stop n Shop.

Thanks guys,

Bill

[PoolDoc]

So will I be adding 4 gallons a night for about 4 nights?

No, you'll be adding 4 gallons per night, till you can hold a residual. Trying to analytically predict doses like that ends up being a distraction. You might be right -- but you'd still get there just as surely without the prediction.

Or, you might be wrong, and then pause, and come back here asking what to do. That would slow things down for everyone.

Testing and dosing is not so precise -- in the pool biz -- that predictions work especially well. So instead of testing and then dosing . . . . test, then dose, then test and dose so more till you get there. Works every time!

PoolDoc

[herrmanncr]

I am having the same problem. "Chlorine lock". I googled and it braught me here. Don't mean to jump in but need to know how much bleach to use. Posted #s last night but didn't show.Pool is 21000 ig vinyl.
Off memory think they are
Fc .2
Ph 7
Alk 130
Calc 400
Cya 94
These are pool store #. I need to get a kit.
Any help is appreciated. Water is clear for now. Been shocking with all kinds. Usinf algea 60. No metals present.
Thanks , chris

[aylad]

herrmanncr,

I answered this in your thread. It is helpful if you'll keep your information in that thread that you started, because it gets really confusing for those trying to help two different posters within the same thread. I promise that we're looking at yours as often as we are looking here! It doesn't hurt to read other, similar threads, but please keep your pool details in your own thread to make it easier on us.

Thanks!

Janet

[CarlD]

The way I worked the math was with a proportion. If .5 teaspoons effectively chlorinates 1 gallon of pool water, then 12000 teaspoons should effectively chlorinate 24000 gallons. Converting 12000 teaspoons to gallons gives me 15.625 gallons of bleach. Am I correct? So will I be adding 4 gallons a night for about 4 nights?

I'm not sure how you go there, but ultimately the calculation is correct.

Here's the formula you need:
(1,000,000/pool size) * concentration of bleach * # gals bleach = FC added

or, in your case, using 6% bleach

(1,000,000/24,000) * 0.06 * 4 gallons=9.99ppm of free chlorine added per night.

But you cannot be sure with that, as Ben says. You must still be testing because chlorine will be consumed.

For a 24,000 gal pool, one gallon of 6% bleach adds 2.5ppm of FC.

[btozzo]

Got it. I was just trying to get a sense of how much this will cost me. I was planning on testing and dosing until I got there and then testing some more!

I'm going to start tonight and I'll be posting my results daily. Thanks so much everyone, I'm seeing some light at the end of my "No Chlorine Tunnel!"

Bill