CYA testing...

[EricJ320]

Moved from here.
So I need a little help, I have to admit I’m baffled. Well, I have my suspicions, but I don’t want to mislead any advice so I’ll wait and see if I’m right. Testing for CYA has always seemed a bit of an inaccurate science to me, but I don’t recall having any major issues last season, albeit my first full pool season. I don’t close my pool, and while I have had to drain a couple of times this winter from rain, it didn’t seem to be as much as my CYA tests would reflect, but, my salt was also lower than I expected, so that seem to validate the low CYA levels I have been getting.

I’m a little paranoid about putting too much CYA in, so before adding any I ordered a bottle of R-7065 50ppm standard someone linked above to help make sure I’m seeing this little black dot as I’m supposed to. I did the test with the standard, and it’s not cloudy at all. The dot is nearly as visible as it would be with water. I fill the test tube completely full and it’s pretty much the same as at the 50ppm line. My original T-2006 R-0013 CYA reagents had an expiration date of 10/21, I order a 2oz bottle to refill them last September, and that bottle has an expiration date of 6/22.
We’ve been getting some longer sunny days this week, and my chlorine levels have been pretty constant, so I believe my CYA level is nowhere near as low as my initial tests have been showing. I’d really rather put this bag of CYA on the shelf and save for later than over load it in the pool because I’m getting erroneous test results.
What do you guys suspect is going on here. I’m using what should be good reagents, I’m doing the test with room temperature water, and I’m following the instructions exactly as it says and I have always done. Any help would be greatly appreciated.

 

[Rancho Cost-a-Lotta]

I remember recently someone performed the test using only the standard without mixing in the R-0013 reagent. Not saying you did it, just reminiscing.

 

[wireform]

Moved from here.
So I need a little help, I have to admit I’m baffled. Well, I have my suspicions, but I don’t want to mislead any advice so I’ll wait and see if I’m right. Testing for CYA has always seemed a bit of an inaccurate science to me, but I don’t recall having any major issues last season, albeit my first full pool season. I don’t close my pool, and while I have had to drain a couple of times this winter from rain, it didn’t seem to be as much as my CYA tests would reflect, but, my salt was also lower than I expected, so that seem to validate the low CYA levels I have been getting.

I’m a little paranoid about putting too much CYA in, so before adding any I ordered a bottle of R-7065 50ppm standard someone linked above to help make sure I’m seeing this little black dot as I’m supposed to. I did the test with the standard, and it’s not cloudy at all. The dot is nearly as visible as it would be with water. I fill the test tube completely full and it’s pretty much the same as at the 50ppm line. My original T-2006 R-0013 CYA reagents had an expiration date of 10/21, I order a 2oz bottle to refill them last September, and that bottle has an expiration date of 6/22.
We’ve been getting some longer sunny days this week, and my chlorine levels have been pretty constant, so I believe my CYA level is nowhere near as low as my initial tests have been showing. I’d really rather put this bag of CYA on the shelf and save for later than over load it in the pool because I’m getting erroneous test results.
What do you guys suspect is going on here. I’m using what should be good reagents, I’m doing the test with room temperature water, and I’m following the instructions exactly as it says and I have always done. Any help would be greatly appreciated.

Are you doing it outdoors with bright sun behind you and the test in your shadow.

 

[EricJ320]

Are you doing it outdoors with bright sun behind you and the test in your shadow.

I’ve tried it outside with the sun at my back, in the shade, inside with moderate indoor lighting, test tube at my waste, watching as I fill, glancing at different levels so not to just stare at the dot, no matter how I do it I’m getting very low test results. Like I said, with the standard it looks like water, I can’t imagine any lighting, or lack there of making it look any different, the dot is very clearly visible. I did the test fine last year, so I’m fairly sure I’m doing it correctly, I simply got the standard to help calibrate my results to a known result. It hasn’t worked out like I had hoped. I guess I’m questioning my refill reagent as my first thought. I guess it could be the standard at fault as well, but that wouldn’t explain the unusually low results using the pool water.

 

[wireform]

Are you saying the standard used by itself in the tube shows nothing too?

 

[AUSpool]

I suspect your cya is a bit low but a near zero result for a 50ppm standard is a worry. You could have a dud standard or a dud reagent. But as they say, show me the numbers. Where were you at the end of last summer? What was your salt at the end of last summer and what it it now?

First up is the test. A seven ml sample at room temp in the test bottle. Add 7ml of the R0013, cap and shake for 30 seconds. The standard is treated the same as a sample. Then fill the comparator till the dot disappears.

From hear there are options, are you testing right, get a new standard, get a new reagent. Or abandon the standard, add a small dose, say enough to get from 0 - 30ppm, to your pool and test with your current reagent.

 

[Rocket J Squirrel]

I never had any luck with the standard solutions. I bought them all and none of them gave reliable readings.

 

[mguzzy]

I'm not sure whats going on with your standards.. but keep in mind that CYA degrades with time, add to that the dilution you are having from rain. Its pretty typical to have my CYA be less than a quarter what it was at the end of the previous season. I always bring it up in stages so I don't over shoot the target.

 

[duraleigh]

So, confirm you are doing the test correctly.

The CYA Standard test is by mixing 50% standard solution and 50% R-0013 in the test vial. Are you doing that?

 

[EricJ320]

So, confirm you are doing the test correctly.

The CYA Standard test is by mixing 50% standard solution and 50% R-0013 in the test vial. Are you doing that?

Yes, whether I’m using sample pool water, or the standard, I fill the bottle to 7ml, raise with R-0013 reagent to 14ml and shake for a min of 30 sec. All samples are at room temp and like I said, I’ve looked in several different light sources and the dot is not only visible, it’s what I would call barely clouded. Below is a picture with the standard raised to the 30ppm line, at a large window with my back to the window. Sample at waste level with the camera just below my shoulders.

 

[EricJ320]

I suspect your cya is a bit low but a near zero result for a 50ppm standard is a worry. You could have a dud standard or a dud reagent. But as they say, show me the numbers. Where were you at the end of last summer? What was your salt at the end of last summer and what it it now?

First up is the test. A seven ml sample at room temp in the test bottle. Add 7ml of the R0013, cap and shake for 30 seconds. The standard is treated the same as a sample. Then fill the comparator till the dot disappears.

From hear there are options, are you testing right, get a new standard, get a new reagent. Or abandon the standard, add a small dose, say enough to get from 0 - 30ppm, to your pool and test with your current reagent.

Looking back through Pool Math, i don’t remember it being 30ppm last fall, but it’s what the app says, so I have no doubt that’s what it was. And the time frame coincides with ordering of the new R-0013, so I’m sure that’s why I had reordered to do additional tests before adding CYA. My salt dwindles through the summer and fall, and CYA will as well of course. I don’t have a leak, the water level does not change through out the winter, but for the most part 2 young kids contribute to water loss during the summer, but mostly we have 3 large dogs, one a 150lbs Mastiff that takes a lot of water out with him. Even still I don’t often have to fill, usually rain water is enough, but not always. My last salt test in the fall had dropped to 3000, first test this month showed 2400 and the low salt light was on. I put 80lbs of salt in the other day, that raised it to 2800, I added 120lbs yesterday and it tested last night at 3400. I have no doubt my CYA is low, and I like your idea of putting enough in to raise it 30ppm and see what results I get on that test. I thought I had it figured out, but this standard test is throwing me for a loop.

 

[wireform]

I want to be sure I'm understanding. Are we saying the standard you purchased is supposed to show 50ppm on the test tube ? Then why would you fill the vial only to 30 or did I miss it totally.

 

[EricJ320]

I want to be sure I'm understanding. Are we saying the standard you purchased is supposed to show 50ppm on the test tube ? Then why would you fill the vial only to 30 or did I miss it totally.

In case you aren’t familiar with the Taylor test, the more CYA in the water, the cloudier the test sample gets. The more water you have to add to lose visual of the dot, the less CYA is in the sample. In the standard case, the test should reflect a 50ppm result, I fill it to 50, the dot is almost 100% visible. I then fill the tube all the way to the top of the scale, 30ppm, that’s what the picture shows. I used that as a reference to show not only is it not reflecting 50ppm, it’s not even obscuring the dot at 30ppm, which is significantly more sample water. So when you say I “only” added to the 30ppm line, that’s actually more sample water than at 50ppm.

 

[wireform]

Got it, didn't think it through enough.

 

[AUSpool]

So your confident about doing the test right and your R0013 is OK or within date. I think you have low CYA and a dud standard. Standards can cause confusion. Through last summer your CYA went from 65ppm down to 30ppm which is understandable and quite normal. Your salt has dropped and so would your CYA.

I would abandon the standard and make your own in your pool. Testing can be tricky at or below 30ppm so I would add enough to bring you up to 40ppm. @ 22500g, PoolMath calculates 120oz but do the math yourself to double check. I would guess your likely at 0 - 10ppm CYA now so that 120oz dose would bring you up to 50ppm. You’ll eventually want to get up to 70 - 80ppm for summer with a SWCG. You can be conservative and add the 120oz in two doses of 60oz but be aware that ~30ppm or less may be hard to detect.

If you add the full 120oz and still get a low to zero result it’s time for some more R0013.

 

[duraleigh]

I haven't read this thoroughly but a more logical conclusion to me is that you have no CYA. Have you tried going to a pool store to see if they get 0 CYA as you do?

 

[dbalzan]

You could validate your CYA testing by mixing stabilizer into a bucket of water at 200ppm concentration. If that tests low then you have a dud reagent.

 

[EricJ320]

So your confident about doing the test right and your R0013 is OK or within date. I think you have low CYA and a dud standard. Standards can cause confusion. Through last summer your CYA went from 65ppm down to 30ppm which is understandable and quite normal. Your salt has dropped and so would your CYA.

I would abandon the standard and make your own in your pool. Testing can be tricky at or below 30ppm so I would add enough to bring you up to 40ppm. @ 22500g, PoolMath calculates 120oz but do the math yourself to double check. I would guess your likely at 0 - 10ppm CYA now so that 120oz dose would bring you up to 50ppm. You’ll eventually want to get up to 70 - 80ppm for summer with a SWCG. You can be conservative and add the 120oz in two doses of 60oz but be aware that ~30ppm or less may be hard to detect.

If you add the full 120oz and still get a low to zero result it’s time for some more R0013.

I was originally thinking dud reagent, but after having looked back in the past and seeing what my end of season CYA level was, I agree it’s looking more like dud standard. While that‘s an easier and cheaper fix, it wont be awesome to find out I wasted $10 at TFTestkits to get what I thought was helping to educate me on accurately reading this test. I realize this forum and the test kit site are virtually one and the same, if it’s confirmed the standard is a dud I would hope that situation would get rectified appropriately.

I haven't read this thoroughly but a more logical conclusion to me is that you have no CYA. Have you tried going to a pool store to see if they get 0 CYA as you do?

I’m always a little reluctant to get tests at pool stores. I would if I could find one that believes in the TFP method, otherwise they just seem to tell me I’m doing it all wrong and look at me like I have 2 heads. Not to mention I’ve always questioned their accuracy as well. I guess I could do that and just learn how to hit the ignore button!

You could validate your CYA testing by mixing stabilizer into a bucket of water at 200ppm concentration. If that tests low then you have a dud reagent.

That’s a pretty good idea. Looks like just under 2 grams of stabilizer for a 5 gallon bucket should net me close to 100ppm. I’ll try that tomorrow and see what the results look like.

 

[mguzzy]

always a little reluctant to get tests at pool stores. I would if I could find one that believes in the TFP method, otherwise they just seem to tell me I’m doing it all wrong and look at me like I have 2 heads. Not to mention I’ve always questioned their accuracy as well. I guess I could do that and just learn how to hit the ignore button!

I get it.. the big pool store chains give me the heebeegeebies too.. If going into a pool store gives you hives, then try a test strip... just something to give you a ball park value. But it sounds like you are trying to see if your getting any reading at all. Now excuse me while go to the TFP confessional for suggesting someone use a test strip.

 

[AUSpool]

Nothing is ever truly wasted, just recycled, your $10 has turned into a good learning opportunity. High accuracy standards and calibration solutions can be very expensive. There is nothing supper accurate about the CYA disappearing dot turbidity test but it is accurate enough for our needs.

Good on ya for staying out of the LPS’s and doing it yourself.