Chlorine not registering

Causes and cures for cloudy swimming pool water.
Milky pool water, white, pink, brown, purple, black cloudy water.
James Watson

Chlorine not registering

Postby James Watson » Fri 17 Sep, 2010 22:03

467 ounces is fine. It should raise the FC to about 17 ppm. Test FC and CC in about an hour, if you get a chance. Retest again in the morning. Keep raising the FC to 10 to 15 ppm. Once we get about 3 days of results, we can better determine what is happening. The pool is fine to use at 10 to 15 ppm.

Add 4 pounds of baking soda when you get a chance.


shhurs
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Chlorine not registering

Postby shhurs » Sat 18 Sep, 2010 07:50

tested at 7:30 am
shhurs
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Chlorine not registering

Postby shhurs » Sat 18 Sep, 2010 07:53

Tested at 7:30 am
fc 2.0
cc 1.8
ph 7.2
akalinity 110
ch 260
cya 100 (a little high)

i'll go ahead and add the bleach and pick up some borax/baking soda today.
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Chlorine not registering

Postby duraleigh » Sat 18 Sep, 2010 11:00

FC 2.0 You are wa-a-ay too low. With your CYA as high as it is, I suggest you use around 25-30ppm to shock the pool (which you need to do) and hold it there until your CC's drop below .5ppm

CC's 1.8ppm This test result indicates the need to shock your pool.....even though your water may be crystal clear, this needs to be .5ppm or lower and high FC is the only way to get it down.

pH and TA are fine. I would leave them alone for now. CH of 260 is fine, too.

CYA 100 = Here's your largest problem. The reason you need your chlorine so high is because your CYA is too high. However, I assume you are approaching the end of the swim season, so I wouldn't adjust this right now. I would wait 'til Spring and then make a very determined effort to get your CYA down below 70......You'll probably have to do a partial drain and refill.

Your numbers indicate you need to keep your FC at shock level (30-35ppm) until that CC result goes below .5pp. Even then, just maintenance level for your FC should be between 6-9ppm or you will risk another algae bloom.
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shhurs
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Chlorine not registering

Postby shhurs » Sat 18 Sep, 2010 12:36

ok; I shocked. Still need to keep adding 6% bleach and the baking soda/borax as Watson stated?
James Watson

Chlorine not registering

Postby James Watson » Sat 18 Sep, 2010 14:52

Based on the amount of bleach you added last night, your FC should be much higher. The FC loss along with the CC level indicates the need to shock.

Keep testing and adding enough bleach to maintain 25 ppm until the FC levels lose less than 1.5 ppm overnight and the CC is 0.5 or less.

You should use the 10 ml line and count every drop as 0.5 ppm instead of the 25 ml line, where every drop is 0.2, to save on reagent.

A pH of 7.2 is fine for now. Bleach causes some pH rise, so you should not add anything for the pH.

I hope you can see how fast the cyanuric acid can build up from using tabs. Back on September 07, it was at 30 ppm and now it is already 100 ppm. This is why we caution people about using tabs.
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Chlorine not registering

Postby chem geek » Sat 18 Sep, 2010 19:48

For every 10 ppm Free Chlorine (FC) added by Trichlor tabs/pucks, it also increases Cyanuric Acid (CYA) by 6 ppm. So even with an unusually low 1 ppm FC per day chlorine usage, that's over 100 ppm CYA added in 6 months if there is no water dilution.
James Watson

Chlorine not registering

Postby James Watson » Sun 19 Sep, 2010 00:52

Also, note that the cyanuric acid test is not always very accurate. For your cyanuric acid to have gone up by 70 ppm, you would have had to use about 14 pounds of trichlor tabs. That's a lot of trichlor to use in less than two weeks. There was probably some inaccuracy in the testing.

You should consider getting extra chlorine reagents. Using the 10 ml sample size, you will still use 50 drops when testing FC at 25 ppm. I recommend an extra bottle of the R-0870, and a 2 ounce bottle of the R-0871.

Hopefully, you will only have to maintain 25 ppm for a few days until all of the organics are oxidized.
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Chlorine not registering

Postby shhurs » Sun 19 Sep, 2010 12:04

I'm not getting anywhere near those amount for FC. We had an inch of rain overnight and here's my results from this morning.
FC 1.0
CC .4
pH 7.2
TA 100
CYA 95

When using OTO to test for chlorine it measure 5.0 easily. As a dummy about most of the rationale for all this, in simple terms, why the difference in this test result than that with my Taylor kit?

I'm thinking I'm going to close for the season here soon. Should I continue all this?

I have not added tabs to the amount you mentioned. I think I'm using the test kit correctly but I am a novice.
James Watson

Chlorine not registering

Postby James Watson » Sun 19 Sep, 2010 13:44

Chlorine (Free, Combined) Test

1. Rinse and fill large comparator tube to desired mark
with water to be tested.

NOTE: For 1 drop = 0.2 ppm, use 25 mL sample.
For 1 drop = 0.5 ppm, use 10 mL sample.

2. Add 2 dippers R-0870. Swirl until dissolved. If free
chlorine is present, sample will turn pink.

NOTE: If pink color disappears, add R-0870 until
color turns pink.

3. Add R-0871 dropwise, swirling and counting after
each drop, until color changes from pink to
colorless.

4. Multiply drops in Step 3 by drop equivalence (Step 1).
Record as parts per million (ppm) free chlorine (FC).

5. Add 5 drops R-0003. Swirl to mix. If combined chlorine
is present, sample will turn pink.

6. Add R-0871 dropwise, swirling and counting after each
drop, until color changes from pink to colorless.

7. Multiply drops in Step 6 by drop equivalence (Step 1).
Record as ppm combined chlorine (CC).
http://www.taylortechnologies.com/produ ... umber=5138


Here is a page with videos that shows how to do all of the tests. Choose "To Test (Free and Combined)Chlorine using FAS-DPD".
http://www.taylortechnologies.com/produ ... ber=K-2006

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