I am running a salt chlorinator and this year put a safety cover on my pool in early October. I made sure the salt level was around 3100 ppm before putting on the cover (suggested range). I turned the generator down from 40 to 20 % and left the low speed pump running without testing the water chemistry but checking the salt level (which is automatic and doesn't require removal of the cover.) After a lot of rain, I pulled back the cover to put more salt in and tested the water. I have been unable to get an accurate reading with any test kit. I have ordered the Taylor 2006. What I did notice is that the OTO fluid in the yellow bottle did not mix with the pool water but looked turned dark orange and appeared like little drops kind of like oil trying to mix with water. I then tested straight bleach in my tester, and the OTO did something similar. I tested distilled water in the tester, and the OTO did not change color as expected. So, I've concluded that I have basically bleach for pool water.

I have tried Leslie's Chlorine Reducer but all it did was allow the OTO to mix with the water but is still dark orange. Perhaps I need much more, but I don't know how much as I don't know how high the chlorine level is. I've also left the cover off for several days and the sun has been shining. I've tried the dilution method of testing (1 part pool water to 2 parts distilled water) and have been unable to get a good reading even when I change the ratio to 1:10. I tried using all distilled water and only a drop of pool water with only 1 drop of the OTO fuild instead of 5 and the color was in a normal range then. Any ideas how I should proceed?

I don't plan to close the pool for the winter, but I will keep the pump running to avoid freezing. I have a high water table so I can't drain the pool in the winter either.

Thanks for any help!

Dilute a glass of pool water 50-50 with tap water, test the mixture and then double your reading. If it's still too dark, go for 3 parts tap water to one part pool water. It's not real accurate since the tap water has a little chlorine in it, but it will give you an idea.

Thank you for your quick reply. I think my test with distilled water is pretty much the same test you are talking about except a little more accurate since there isn't chlorine in distilled water. I tried 1 part pool water and 10 parts distilled without being able to get a reading.

Is the SWG now set to 0%? Can you leave the cover open for now?

Do you know what the stabilizer level was in October?

3 % hydrogen peroxide will lower the chlorine about as much as 6 % bleach will raise it. Add the hydrogen peroxide in stages until the chlorine is in the correct range.

To estimate how much hydrogen peroxide you will need, get a gallon or two of pool water and add hydrogen peroxide a little at a time to see how much it takes and then scale up the amounts.

1 drop of H2O2 is about 0.05 milliliters. Therefore, if you use 1 gallon of pool water and your pool is 30,000 gallons, then every drop will equal about 1.5 liters of H2O2 needed to lower your chlorine level.

4 milliliters of hydrogen peroxide in 10 liters of water will neutralize 25 ppm of chlorine. You can start there to get a rough estimate. Add 4 ml stir, retest and continue until you get no chlorine reading.

You can also use the model of the salt cell to determine the amount of chlorine produced. For example, the IC 40 produces 1.4 pounds of chlorine gas per day. At 20 %, it will produce 0.28 pounds of chlorine gas per day. For a 30,000 gallon pool, that would be 1.12 ppm per day. For 60 days, that would be 67 ppm.


How many gallons is the pool?

If you go the peroxide route, don't smoke while you do it. Also, don't pour it in all in one spot, but around the pool. I have not run the calcs, but I know it releases pure oxygen, and in a lab environment requires ventilation and flame exposure safeguards.

Caution should always be used when handling any chemicals. However, I think that using 3 % in a pool should be safe. The amounts would be so dilute, that there would not be any concentrated oxygen release. In a lab, the chemicals are much more concentrated. People should not smoke when handling any chemical.

If one were using a stronger hydrogen peroxide, such as Baquacil Shock and Oxidizer, which is 27 % hydrogen peroxide, then there would be more reason to be careful, but mostly from direct exposure to the concentrated hydrogen peroxide.

If you were going to mix 3 % hydrogen peroxide directly with bleach to neutralize bleach*, that would cause a lot of concentrated oxygen to be released.

http://www.youtube.com/watch?v=dDCdx6g3R-E

*I have done it, and it works, but I don't think that it is something people should do.

I just had a much more hilarious idea.... just get all your neighbors to come pee in your pool. That should use up the chlorine pretty quickly. (dont really do this please! But if you do we want a humorous write-up!)

Funny! Hadn't thought of the pee, but I'm not sure all my neighbors having a pee party would even do it. I ordered a Taylor K-2006 test kit, got it in and tried to get a good test with the 10 ml sample size. I hate to use all of my reagent on day 1. I'm already up to 75 drops and still have pink water. That means I'm over 37.5 ppm of free chlorine. My pool is 14,000 gal., vinyl liner.

Based on the size of the pool, assuming minimal loss of FC, and assuming an IC 40 cell, I think that your FC might be around 80 to 140 ppm.

You can do a 9:1 dilution with distilled water and then multiply the results by 10 to get a rough estimate of the FC level.

What is your cyanuric acid level?

Note: You don't want to dilute with tap water when testing for FC because that can introduce an error equivalent to the concentration of chlorine in the tap water multiplied by the dilution factor if the tap water contains Free Chlorine, or -1/2 of the concentration of monochloramine in the tap water multiplied by the dilution factor.

For example, if the tap water contained 2 ppm FC and the dilution factor is 9:1, then there will be a +18 ppm error in the tested amount. If the tap water contained 2 ppm monochloramine and the dilution factor is 9:1, then there will be a negative 9 ppm error in the measured amount (assuming that the FC fully oxidizes the monochloramine).

With this cold weather we are having ~ 29 deg lows, water temp is 48 and I had to turn my swg off a few days ago, as even at 5% it was producing too much!

Pretty much the same here. I'm running my pump for four hours a day with my SWCG at 5%. One of the benefits of a large pump and oversized SWCG.

The last two nights the freeze protection activated and my chlorine went up to about 9 ppm. I'll keep the SWCG off for a few days.

SWG has been off for almost 2 weeks. Water temp is 49. Cyanuric Acid test appeared to be 0 as the black dot (K-2006 Taylor test kit) was never covered and the water + reagent solution was not cloudy. Going to get distilled water for another dilution test. Thanks to everyone for all the help!

What city and state do you live in? Is your pool still covered?

Murfreesboro TN (near Nashville). It has been uncovered for most of the 2 weeks now.

I would let the FC drift on down on it's own. I am surprised, even with the cool water temp, that it hasn't been reduced drastically because you have no CYA and the cover is off.

Nevertheless, it will come down into testable range soon and then you can monitor it more carefully. How does your water look? I assume it is quite clear.

It is clear with a slight yellow tint. No slime at all. Leaves that blew in under the cover turned white.

In the meantime you can use it for laundry pre-soak for your whites!