Trouble with cya reading

[keithpgdrb]

Hey all. Just got my tf-100 test kit today. I ran the cya test and I am getting no reading. Liquid stays clear. This implies that I have 0 cya. However. My colorQ tester said yesterday that I had 76. The pool store read it at 55.

I’m having trouble believing that I have 0.

One possibility is that I pulled my sample around 7:30, and didn’t test till about 11. Would this timing change anything?

Do I have bad reagent? I’ll try testing again tomorrow with fresh from the pool water. Advice?

Also. When testing my chlorine. After the liquid turned clear again, I let it sit while I read the instructions. It started to get pink again. If I add more of the clearing agent it goes back. Normal? Is this a time sensitive test?

 

[wireform]

How and where are you testing the CYA as you need full sun from behind you with the test tube at your waist.

 

[keithpgdrb]

How and where are you testing the CYA as you need full sun from behind you with the test tube at your waist.

I’ll admit, I am inside. At night with all my kitchen lights on. I thought it was bright enough. Should the sample look a little cloudy? Mine does not.

 

[wireform]

Outdoors in bright sunlight may have somewhat different results.

 

[keithpgdrb]

I am definitely not good at these drop tests. I’m getting odd readings everywhere. Regent implies like 7 chlorine. Color q says 4.5. Regent looked like over 8.2 ph. Machine says 7.8. Alkalinity test was consistent. Too high. Ugh. I’ll have to practice more with this. I just wish there was a more dependable cya test.

 

[wireform]

Droplet bottles need to be inverted completely and not on an angle. Don't force the drop but let it fall off the tip almost by itself.

 

[Jimrahbe]

Keith,

I have the ColorQ Pro 7 and find the following.

FC is almost always 1 or 2 ppm lower than my TF-Pro (TF-100).
pH is almost always about .2 ppm lower than my TF-Pro
TA is close now that they have updated the TA reagent.
CH is not close because the ColorQ actually measures Total Hardness and not Calcium Hardness which has a lot to do with the local water
CYA depends on the tablets.. some are very close, but other batches of tablets have been off by 20 ppm.

About CYA. I find it hard to believe that your CYA reads 76 on the ColorQ and zero with the TF-100. I suspect some type of test error. The water in the tube should be somewhat cloudy. If crystal clear, something is wrong. Try using your ColorQ with a tube of clear water (no tablet) when running the CYA test and see what it reports.

How have you been chlorinating your pool in the past year?

Thanks,

Jim R.

 

[keithpgdrb]

Keith,

I have the ColorQ Pro 7 and find the following.

FC is almost always 1 or 2 ppm lower than my TF-Pro (TF-100).
pH is almost always about .2 ppm lower than my TF-Pro
TA is close now that they have updated the TA reagent.
CH is not close because the ColorQ actually measures Total Hardness and not Calcium Hardness which has a lot to do with the local water
CYA depends on the tablets.. some are very close, but other batches of tablets have been off by 20 ppm.

About CYA. I find it hard to believe that your CYA reads 76 on the ColorQ and zero with the TF-100. I suspect some type of test error. The water in the tube should be somewhat cloudy. If crystal clear, something is wrong. Try using your ColorQ with a tube of clear water (no tablet) when running the CYA test and see what it reports.

How have you been chlorinating your pool in the past year?

Thanks,

Jim R.

Hey Jim. Thank you for your comments. I have a swg for chlorine. I have been shocking my pool with the bags of powdered shock. Would you believe my color q read my cya as 14 today. That would be consistent with the 100 test. But makes little sense with my past readings. I’m going to concentrate tomorrow on getting some good test results. Maybe Monday actually. Had a gathering today and threw in a bag of shock tonight. That will take some time to dissipate tomorrow. I’m trying to shift to the tfp way of managing the pool, but getting a reliable cya reading is really difficult.

 

[gingrbredman]

Also. When testing my chlorine. After the liquid turned clear again, I let it sit while I read the instructions. It started to get pink again. If I add more of the clearing agent it goes back. Normal? Is this a time sensitive test?

This is common, do not pay any attention to the color of the test vial after you completed the test. Mine will always go back to pink in enough time, but the correct result is the one you get right when you are testing. Add the powder, let it mix up on the speed stir (hope you have that, really the best way!), and add drops until clear. that is the result you record.

I have a swg for chlorine.

Why are you adding powdered shock to the pool if you have a SWCG? Seems with an ic40, you have plenty of capacity to make all the chlorine you need with that. Not sure what else is in that bag, but likely calcium otherwise your CYA would be higher. Would explain the higher ch test in your pool math log, but not sure how that number was tested, doesn't look like a TF100 result.

One tip for the CYA test is to go pick up a 50ppm "standard" from TFTestkits and see what 50 really looks like. However you need to look at the vial with 50ppm in it, inside, sun, shade, etc., that sample is 50ppm and once you see what it should look like, could be helpful with future CYA testing.

 

[keithpgdrb]

had a gathering yesterday. Pool open most of the day. I do have a fear that my cya is indeed low, because the pool does not hold chlorine being in the sun.

Just ran another set of tests on my color q. I’m going to do the tf100 next. As expected, low chlorine. And low cya.

I did buy some liquid bleach today. Just need to figure out how to use it.

Color q:
Fc 2.92
Tc 3.13
Cc .21
Ph 7.8
Ta 110
Adjusted ta 108
Ch 423
Cya 10

 

[Mdragger88]

I did buy some liquid bleach today. Just need to figure out how to use it.

Pour it in slowly in front of a running return, brush the area afterwards. Use PoolMath to calculate amounts.

 

[Jimrahbe]

Keith,

If you have been using bags of Pool Store "Shock, then I am shocked that your CYA is so low.

Thanks,

Jim R.

 

[keithpgdrb]

Keith,

If you have been using bags of Pool Store "Shock, then I am shocked that your CYA is so low.

Thanks,

Jim R.

I purposely got stuff without cyn so it wouldnt get too high. I was afraid of the "lock" at the time.

Just finished testing using the TF-100 kit.
FC 4.5
CC 1.5
CH 300
TA 110/120
PH 7.8
CYA couldnt get any reading. solution was completely clear. This sounds consistent with my experience.

I have turned my SWG up to about 75%
what should I do first.

 

[Jimrahbe]

Keith,

In your area I would assume that you will be closing soon. Is that true?

I'd add enough CYA to bring the level up to 30 ppm. Adding 64 oz of dry stabilizer will give you 30 ppm of CYA

Then attack it next year after you open.

I assume you know this, but your salt cell will not work once the water gets down to below 52 degrees.

Thanks,

Jim R.

 

[keithpgdrb]

Keith,

In your area I would assume that you will be closing soon. Is that true?

I'd add enough CYA to bring the level up to 30 ppm. Adding 64 oz of dry stabilizer will give you 30 ppm of CYA

Then attack it next year after you open.

I assume you know this, but your salt cell will not work once the water gets down to below 52 degrees.

Thanks,

Jim R.

Closing mid October. I’ll get some cya in there. Glad my calcium wasn’t too high to have to drain. Right?

 

[Mdragger88]

The high cc’s are a tad concerning.
do you have a cover on this pool? If so, leave it uncovered so the sun can help with the cc’s. After adding some cya to protect the fc as Jim mentioned. Follow the liquid chlorine side of the FC/CYA Levels since you are running a low cya. A cover traps cc’s so it needs to be opened occasionally to allow them to escape. If after taking these steps cc’s don’t come down you may want to do an Overnight Chlorine Loss Test to confirm that nothing is brewing.

 

[keithpgdrb]

The high cc’s are a tad concerning.
do you have a cover on this pool? If so, leave it uncovered so the sun can help with the cc’s. After adding some cya to protect the fc as Jim mentioned. Follow the liquid chlorine side of the FC/CYA Levels since you are running a low cya. A cover traps cc’s so it needs to be opened occasionally to allow them to escape. If after taking these steps cc’s don’t come down you may want to do an Overnight Chlorine Loss Test to confirm that nothing is brewing.

I do have an automatic cover. I closed it this afternoon so I could save what chlorine I had. It was open all morning. I have a feeling I need to sanitize, but need to get some cya in there asap.

 

[Jimrahbe]

Keith,

With an autocover you can get away with a CYA of 30 to 50 depending on how long you leave the cover open each day. As 88 points out above, you need to open the cover each day or so to let the trapped CC's escape.

People like me, who do not have a cover, need to run a CYA of 70 to 80 to keep the sun from quickly consuming all the FC.

FC with zero CYA is actually harsh feeling. A CYA of 30 make higher FC levels unnoticeable.

Thanks,

Jim R.

 

[keithpgdrb]

CYA is almost completely dissolved. So I can test that tomorrow. Should be 30-40 something hopefully

I cranked the SWG yesterday, opened the pool for a couple hours in the sun today.

Pulled some water and it looks like the CC is good now.

FC 9
CC .5 maybe
Ph looks between 7.5 and 7.8. I hate comparing colors.

Put the cover back on and dropped the SWG to 15 percent. Sound like a plan? I have not figured out what setting to keep the swg on as of yet. It will be different now with some acceptable cya.