Chlorine Lock ????

[poolrescue30]

I got my chlorine lock down a bit, pool store still says it's at a 1. I did do the 8 gallons of 6% bleach TWICE already . The pool looks great and the water's fine, but my free chlorine is being "eaten up". i ordered a FAS_DPD kit as well as a Lamotte color proq7, hey it'll be more accuarate than the 18 year old at the pool store .What is the proper CYA level for a 33,000 inground vinyl liner pool ? where is my chlorine going?
Thanks

[CarlD]

CYA level is measured in parts per milion (PPM). That means that the size of the pool is irrelevant. Your local weather conditions and how your water retains chlorine will determine the ideal. As a WAG, in the NE, 30-50 is a good level. In the deep South a higher level of 50 to 70 is preferable.

But you MUST retain the correct residual levels of chlorine for your level of CYA.

[poolrescue30]

OK, I just used the lamotte kit. my numbers are real bad..... Can you please tell me what to do first !!!!

.05 FCL

.96 TCL

7.1 PH

16 ALK

211 CH

92 CYA

THANKS !!!

[CarlD]

First off, there is no such thing as "Chlorine Lock". This is a bit of pool store nonsense and even if there was, you have to have CYA above 150 to 200ppm before you get it--or something that looks like chlorine lock.

How did you get your CYA to 92 from 40????

If that's correct, you need 11 gallons of Ultra bleach....or if you have a pool store that sell 5 gallon carboys of nominal 12%, you'll need the whole thing.

Have the pool store test your water and see if the numbers match your Lamotte test. Electronic testers look cool but they are notoriously inaccurate. You'd do better with a simple WalMart HTH 5-way drop test kit. Don't buy anything the pool store guy tries to sell you but the liquid chlorine--you'll need to put a deposit on the carboy but you can use the empty as the deposit next time.

You need to go back to our various threads on algae fighting--and stick to it. You have been dumping a bunch of stuff in, and hoping it will magically clear it up.

There's no magic, there's no mystery. You need to consistently shock your pool ONLY WITH BLEACH OR LIQUID CHLORINE until the TC and the FC match and your FC levels don't keep dropping rapidly. Some loss over 24 hours is normal, but to go from 15 to 1 in a 8 hours means you are fighting organics. So you should be checking your water 2 to 3x a day and immediately adding chlorine if FC is low and/or not matching TC (remember: TC = FC + CC always and forever--and you want CC to be 0).

The pool store will sell you clarifiers, algaecides, mineral erosion kits, non-chlorine "shock", cal-hypo "shock", phosphate removers, calcium increasers, but they won't sell you what you need: an FAS-DPD Chlorine test kit. So use them for what you can, and buy from them what you cannot get elsewhere. If you find a good, knowledgable pool store salesman, give him your business if his prices aren't TOO unreasonable...I know one and only one of the 10 stores I will go to.

I know you've been working hard. Ordering the FAS-DPD test kit was smart.

I think the hardest two things about fighting algae are:
1) Not panicking
2) Being patient and persistant.
Otherwise, the rules for fighting are very simple:

1) Adjust pH and measure CYA (if you can).
2) Keep your FC at the recommended shock level for that CYA (See the "Best Guess" chart).
3) Use only bleach or liquid chlorine to maintain that shock level, and test it and adjust it 2x to 3x (better) per day. You can do it 4x or 5x a day--you'll use more chlorine but you may kill the algae faster. Expect to use lots of chlorine.
4) Run your filter 24/7.
5) Once a day, vacuum to waste and brush your pool.
6) Be patient and persistent.

*7) Establish a daily regimen of pool maintenance that prevents this happening again.
a. Just test pH and chlorine every day, and adjust if needed.
b. Once a week run all the tests in the FAS-DPD kit (FC, CC, pH, T/A, CYA).
c. If you have a hard pool, test CH too, weekly.
d. If you have a vinyl pool, test CH 2 or 3x a summer--no more is needed unless you have a problem.
e. (you can skip acid and base demand tests--they vary widely depending on conditions and you don't need them--I don't believe the TF-100 even has them, instead having larger amounts of the other reagents).

[poolrescue30]

Hi,
Went to the pool store on Friday my numbers were :

FCL 0

TCL 0.4

CC 0.4

PH 7.3

ALK 0 !!!

CYA 55

So I put in Alkalinity up to raise ALK And I shocked the pool with 8 gallons of 6% bleach.I also put tabs in the chlorinator and turned it up.

Today's numbers were:
FCL 0.0

TCL 1.2

CC 1.2

pH 7.7

Alk 89

CYA 70


Pool Store recommended I use Sodium Hypochlorite 12.5 % to shock , I bought 2 five gallons jugs , how much should I use at one time to shock the pool ?? He suggested 5 gallons tonight, retest tomororw morning and see from there .i want to hit the 20 ppm mark but did not receive my FAS-DPD test kit yet .Any Advice how to proceed.

i have used this pool store for the last 5 years, the other pool store I went to was a new one .I'm gonna stick to the old guy but his chemicals are very expensive .THANKS

[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 ??