Can someone please help me analyze my first water test?

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kat.hayes

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May 13, 2013
34
Southern Cal
I just did my first test and need some help with the analysis of the results.

Info about my pool:
- about 27,300 gallons
- currently has a floater with 4-5 tabs in it
- recently put some PhosFree in the skimmer (I'm trying to use up the remainder of what I previously bought while I'm learning to take care of the pool)
- I'm using a Taylor K-2006

Test results:
CYA
-The amount left in the tube until the black dot disappeared was slightly above the CYA label and did not have a number on the tube (see photo http://imgur.com/XiyeVGj)

Free and combined chlorine results
- it took 21 drops of r-0871 and shaking until the pink went colorless
- adding 5 drops of r-0003 made it a very faint pink
- adding r-0871 took 1 drop to go colorless

Thanks in advance!!!!
 
Well...
You might notice that the divisions on that CYA scale are not equidistant. My guess is that you're probably somewhere around 140-150,
and you're making it worse by using trichlor pucks in the floater.

XiyeVGj.jpg


As for the Chlorine test, did you use a 25 ml sample, or the 10 ml sample? In either case, CC is .5 or less.

Time to study extended-test-kit-directions-t25081.html It will tell you how to do the CYA test to get a better reading than 100+
 
If the black dot disappeared before it reached 100, then your CYA is over 100. You can mix your water one part pool water, one part tap water and use that as your testing sample - then multiply by 2 for CYA. Either way you're looking at replacing water to get CYA down to 30-50. Shocking with CYA that high will be very difficult and expensive.

Using the 10 ml sample for chlorine - 21 drops = FC of 10.5. For the CC test if the sample turns pink you have CC. If it went clear by adding one drop of r-871 then your CC is less than .5.

Notice that CYA of 100 you need to target FC of 12 and never let it drop below 7. Your CYA is higher than that so water replacement will be necessary.
pool-school/chlorine_cya_chart_shock
 
I used a 25 ml sample since I suspected the chlorine was low. Should I take the floater and trichlor pucks out immediately? I will take a look at the link, though is it possible my CYA is 100+ or are you suggesting my result is not accurate?

Thanks.

Richard320 said:
Well...
You might notice that the divisions on that CYA scale are not equidistant. My guess is that you're probably somewhere around 140-150,
and you're making it worse by using trichlor pucks in the floater.

XiyeVGj.jpg


As for the Chlorine test, did you use a 25 ml sample, or the 10 ml sample? In either case, CC is .5 or less.

Time to study extended-test-kit-directions-t25081.html It will tell you how to do the CYA test to get a better reading than 100+
Click to expand...
 
1. So if my understanding is correct, if my CYA is over 100, my chlorine is not working effectively and the only way to lower the CYA is to replace some of my water? How much water are we talking? Some of it? All of it?
2. In the meantime, how do I deal with CYA at this level? Are you saying that there is nothing I can do to deal with it and I need to replace some or all of it?
3. Is the elevated level of CYA likely a result of the tabs in the floater? What else could have gotten it to this level?

Thanks guys.

spidey07 said:
If the black dot disappeared before it reached 100, then your CYA is over 100. You can mix your water one part pool water, one part tap water and use that as your testing sample - then multiply by 2 for CYA. Either way you're looking at replacing water to get CYA down to 30-50. Shocking with CYA that high will be very difficult and expensive.

Using the 10 ml sample for chlorine - 21 drops = FC of 10.5. For the CC test if the sample turns pink you have CC. If it went clear by adding one drop of r-871 then your CC is less than .5.

Notice that CYA of 100 you need to target FC of 12 and never let it drop below 7. Your CYA is higher than that so water replacement will be necessary.
pool-school/chlorine_cya_chart_shock
Click to expand...
 
1) That depends on your actual CYA level. You will need to do the test again with 50% pool water and 50% tap water and double the result. That will give you a better idea of your CYA level.
2) Is your pool cloudy? If so, you will need to shock. That can really only be done with a reasonable CYA level. If it is not cloudy, you will need to maintain your FC at the level recommended for your CYA, which is unknown at this point.
3) The tabs did increase your CYA. Did you use any powdered shock? That also increases your CYA. Those are the only ways CYA increases, aside from intentionally increasing it by using Stabilizer or conditioner.
 
1.) I will redo the test and report back here. Curious, why test again with 50% pool water and 50% tap water? Why add the tap water?
2.)The pool is not crystal clear, it is maybe slightly cloudy...What would happen if I tried to shock with current CYA levels?
3.) My pool guy never warned me about the tabs in the floater contributing to the CYA problem or that there was a CYA problem. He told me at one point that there was too high of calcium so it wouldn't hold chlorine and we might need to drain it...this was when I decided to start looking into things on my own. Now I am ****** that he never mentioned anything about CYA levels being too high or that I should take out the floater.

Thanks guys.

Thanks.
 
1) The tap water dilutes the CYA, so you can measure it. You mix tap water and pool water, which cuts the CYA level in half. Then you do the test, and double the reading.
2) Since you do not know the current CYA, it is impossible to shock. Just for argument's sake, let's say the CYA is 150. That would mean you would have to shock to a level of 33. I believe your FC is currently at 4.2 (21x.2, for the 25 ml sample). To get from 4.2 to 33, that requires 1173 ounces (or just over 9 gallons) of 8.25% just to get to shock level. If you reduce CYA to 50, the shock level is a much more manageable 16, which would only take 481 oz (or almost 4 gallons) of 8.25% bleach to get to.
3) Calcium has nothing to do with chlorine.
 
I just did my 2nd and 3rd tests of the CYA by using half tap water and half pool water, and I followed the instructions at: extended-test-kit-directions-t25081.html which was the same instructions that I had followed for my first test, except I didn't add half tap water and multiply my results by two for the first test.

2nd test was at about 35 so double that = 70
3rd test in a bit more shade was about 30 so double that = 60

1. So the ideal range is around 50, and it seems mine is somewhere between 60 and 70.
2. Based on these results, can anyone give me any advice? I already took the floater with tabs out of the pool.

Thanks!!!
 

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Well first, your latest CYA tests are not consistent with the first. So something is still not right and would suggest testing again at full strength.

If the latest results are correct, you have 2 choices, replace about 20% of the water to lower the CYA a bit. Or just deal with the slightly higher CYA by using a slightly higher FC level. Either way, you have to switch to liquid chlorine to prevent the CYA from climbing again.
 
1. I'm still confused why it was necessary to add tap water and multiply the results by two because the CYA was so high the first time. Wouldn't this alone result in results not consistent with the first?
2. What do you mean by testing again at "full strength?" What is full strength?
3. How did you calculate that I would need to replace about 20% of the water?
4. You said I have to switch to liquid chlorine to prevent the CYA from climbing again. As opposed to using what?

Thanks!!!
 
Your first picture showed a CYA maybe around 150, but hard to say since it was so far below the 100 line. By using half pool and half tap water, mixing that and using the mix with the CYA reagent, you have cut the test result in half. We were expecting the water to show around 70-80 in the second test which when doubling would be similar to the first test.

So either the first test was wrong or the second ones were. I was suggesting doing the test as normal again with all pool water to see if the first test was bad.

The 20% was just reducing the 60-70 by that amount to be closer to 50 ppm.

And yes. No more solid chlorine should be used to avoid the CYA rise.
 
Had the same problem. Drained about 75 percent last summer after a green pool and finding that the CYA was 150 or more. Pool has been crystal clear and sparkles after following all advice on this site. Added borates to 50, CYA down too 25 so I can risk using tabs during extended trips. Short trips I bring the pool to shock level before leaving and have had no problems other than a slightly elevated ph of 8.2 which remains stable. The first thing you MUST do is STOP using those tabs.
 
I just did two more CYA tests with 100% pool water with the following results:

Test 4: 70
Test 5: 70

I did both of these tests in shade so I could better see the dot while looking down on it, and I also added a bit of water to the pool before doing the tests because it was a bit low (can't imagine that would have affected the tests).

All of my tests:

Test 1: 140 - 150
Test 2: 70 (half tap water and half pool water)
Test 3: 60 (half tap water and half pool water) * done with more shade to view dot better
Test 4: 70 (100% pool water)
Test 5: 70 (100% pool water)

1.) So based on the chart, I should have a FC level of 8 and never let it get below 5. Is this all I need to follow?
2.) Should I still consider replacing some water or is this a manageable level of CYA?
3.) Somewhere in Pool School it indicated:

"If you have a SWG or very high levels of direct sunlight, CYA is typically kept between 70 and 80" and somewhere else it mentioned "CYA to between 60 and 80."

My pool gets high levels of direct sunlight, so is my CYA level of 70 a good thing?

Thanks!!!!
 
70 is still on the high side without a SWG. But you're correct on your chlorine levels.

How about posting a full set of test results? Seems like you have a reliable CYA measurement. You could still knock it down to 30-50. I like 50 but my pool gets all day sun.
 
What is considered a full set of test results?

Thanks.


spidey07 said:
70 is still on the high side without a SWG. But you're correct on your chlorine levels.

How about posting a full set of test results? Seems like you have a reliable CYA measurement. You could still knock it down to 30-50. I like 50 but my pool gets all day sun.
Click to expand...
 

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