jblizzle said:
Wife and store do it. I've never tried it...
I'll see what instructions the wife uses, last night she said something about needing to look really closely at the tube - so I'm thinking not waist level.
CYA goes away...
- Thread starter davelinde
- Start date
Wife and store do it. I've never tried it...
I'll see what instructions the wife uses, last night she said something about needing to look really closely at the tube - so I'm thinking not waist level.
I'll say it is testing error at this point. Pool stores on average are notoriously bad with the CYA test, and it seems your wife is having about the same trouble as the pool stores. I suggest to get a bottle of R-7065 CYA standard solution, 50 ppm, to help your wife learn how to do this test. You can order the bottle from TFTestkits.net.
ping said:
Seems it could be... something is up here.
My wife showed me how the test is done (she has a few tests left) and I can see how it could have some high variation due to subjectivity. If she is looking too closely her number could be high, and if the pool store is not looking very closely they could be low and that could explain some of this.
I remember reading temp matters? Is precision mixing key too? eg - where are people making the errors? It would seem that lighting and eyesight matter...
Room temps or swimp temps on the sample to keep that part simple. Not good if too cold. Lighting is important. In bright sunlight with the sun at you back is the best rule to follow. Read it at waste level like that. In fairness, it is one of the harder tests to get a good feel for with lots of people.
Keep in mind you can pour the solution back and forth a few times to see if you are consistent. In fact both of you should to see if you get the same thing.
jblizzle said:
Thanks for the suggestion. That had crossed my mind when I saw how the test was done, but then I forgot. Sounds like a good way to check.
I'll second that!!! Leslies was telling me my CYA was 40 when in fact it was way over 300--at least 340!ping said:
timerguy said:
OK... Our test kit doesn't even go over 100? Is this like Chlorine and there is more than one way to test it?
In our case the pool store seemed to be tracking some logic - the CYA would be low, we'd add it and they'd confirm the CYA was on target again... then it got low again.
Yesterday my wife added a pound of powder. This weekend she will test the CYA level and I'll take a peek at the dot too. We will see.
Yes you use the dilution technique. Fill the bottle to the pool water line, then, full it to the reagents line with tap water. Then pour it out to the pool water line and then put in the reagent. You may have dilute it a number of times before you add the reagent until till it shows less than 100 then multiply that by the number of times you had to dilute it . I had to dilute mine 4 times to get a reading. My math may be a little fuzzy, but after my experience, I'll never trust a pool store test again. I went through both little bottles of reagent in no time-- went to the pool store and bought a bigger one. Finally, I went to the taylortechnologies.com site and bought a pint bottle for less than the one I bought at leslies. Once you get a good reading then you can determine the best way to get your CYA down. Once you get it to a proper lever, you only need to test it weekly and not have to use that much reagent again.davelinde said:
Please don't add more powder until you give all that several days and re-test. It just might save you some heartache and water....
Brushpup said:
Agreed.
BTW - my wife was happy about the idea of getting reagent in bulk. She didn't like this test because she said it was costing more than a dollar per test. She also said that she had been looking at the tube as close as possible and really trying to study it to see if there was any outline of the dot visible... I'd guess that was making her results too low - so I am curious what we'll see tomorrow.
Well, you might mention that even if it costs 2.00 per test it's no big deal, because you don't need to do it that often, and it's extremely important.
Once you get it adjusted, there is little need to test again for a good while. A few times per summer is usually adequate. Those pool store tests aren't free when you pass through the checkout counter every time you go in there.
Once you get it adjusted, there is little need to test again for a good while. A few times per summer is usually adequate. Those pool store tests aren't free when you pass through the checkout counter every time you go in there.
Brushpup said:
We are learning... this is the first pool we've ever had and we keep it open all year. We kind of stumbled into this cycle by not testing more than once a month and using a combo of the pool store test and our test.
Today I did the test with my wife. It is quite subjective and even at waist level it seem I could always see a faint outline of the dot. If we went by "the dot disappeared, mostly if you didn't keep staring at it" I guess the CYA is between 70 and 80 now. If we went by "dot, what dot?" then it might be lower.
Now that I have a reference point in mind I might be able to see if it drops over the next month. I think we have 3 tests left.
A bonus in your case is one of design. TFPC has set the "goals" that have a wide range. Worrying about a CYA level between 60-80ppm isn't a major concern. The suggested chlorine levels for 60 are a FC level of 5-9ppm. At 80 it only raises to 6-11ppm. Keeping your chlorine level around 8-9ppm will keep off algae. This time of the year you shouldn't drop that much chlorine daily due to little sun, so little worries there either.
Slow your additions down until you fully know what your pool needs. Swings up and down often leads to added expenses due to chemicals being used that are simply not needed.
Slow your additions down until you fully know what your pool needs. Swings up and down often leads to added expenses due to chemicals being used that are simply not needed.
Good deal, and we are here to help. This test isn't the easiest to get a good feel for, but you are getting there. Sounds like you are ok for now. Let it ride for a little while and go from there.
So... it's a month later and DW decided to test CYA again. I did not see the dot but she told me her test now reads 40 ppm and she is back to the pool store for a couple more pounds of CYA. It seems it's going away again 
It was cold so we've had the cover on. We've been checking chlorine only and with the cover on the FC loss has been minimal, in fact we turned off the SWCG for a week or two because we were gaining chlorine at the lowest duty cycle. The other day I added about 2" of water because the water level did drop. Today we pulled off the cover and the water is nice and clear. But alas - lacking that pesky acid.
It was cold so we've had the cover on. We've been checking chlorine only and with the cover on the FC loss has been minimal, in fact we turned off the SWCG for a week or two because we were gaining chlorine at the lowest duty cycle. The other day I added about 2" of water because the water level did drop. Today we pulled off the cover and the water is nice and clear. But alas - lacking that pesky acid.
So... it's a month later and DW decided to test CYA again. I did not see the dot but she told me her test now reads 40 ppm and she is back to the pool store for a couple more pounds of CYA. It seems it's going away again
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Have you considered performing these routine tests more often? If your CYA was stable it doesn't need frequent tests but its hard to know what condition it is in since either it or the testing is so inconsistent.
Do you have a TF-100 test kit? It is a good investment for frugal pool care. In my opinion there is a difference between being frugal and being cheap. Cheap/free pool store testing appears to be worth what you pay for it.
yes, we tested after the water was topped off.
The CYA, we were not testing more often - but I suppose we could watch it decline with more data points if that can help us figure out what's up...
Yes, we have a good test kit with the reagents to test this ourselves. The latest result was our test, not the pool store.
One notable thing... We raised the FC level and then covered the pool. This meant that the FC level stayed pretty high for pretty long. DW was using the less expensive tests and only knew it stayed over 10ppm for quite a while. From other threads here, maybe that's what did it. We will see how it goes from here.
The CYA, we were not testing more often - but I suppose we could watch it decline with more data points if that can help us figure out what's up...
Yes, we have a good test kit with the reagents to test this ourselves. The latest result was our test, not the pool store.
One notable thing... We raised the FC level and then covered the pool. This meant that the FC level stayed pretty high for pretty long. DW was using the less expensive tests and only knew it stayed over 10ppm for quite a while. From other threads here, maybe that's what did it. We will see how it goes from here.
The CYA does get slowly oxidized by chlorine, but in a pool it's usually at a low rate of 2-3 ppm CYA per month and in a hot spa at 5 ppm CYA per month. Technically, it would go away faster at higher FC levels and at higher pH, but it shouldn't be by as much as you are seeing so that's strange though you did see in the post from dschlic1 that very rarely some strange things can happen (maybe there's a rare chlorine-resistant algae species that can biodegrade CYA -- in the scientific literature it's only some bacteria that can do that, but one never knows). You said you have your temperature on the high side, so perhaps you've got your pH high as well, but even with high FC a high pH and warmer temps I wouldn't expect it to be more than 10 ppm CYA per month. Of course, a leak and refill or other water dilution could lower the CYA level as well, but would tend to lower other levels such as CH unless the fill water was high in CH.