Tf 100 test kit "CYA" question

[BigBrownLog]

I recently recieved my tf 100 and love it. I've done the CYA test twice now and it reads 20ppm. i had 80ppm a month ago. we have only had one hard rain. and we filled the pool 3 times about 2-3" of water each time.

pool store says i have 54ppm and i know they dont do it rt but it cant be that far off can it?

when i read the test when do i consider the black dot gone cause i can still see it a little bit at 20 very very faint but i can see it.

 

[JohnT]

If it's faint at the 20ppm line, then your CYA is less than 20ppm. Measure when you can't see the dot at all.

 

[duraleigh]

BBL,
Taylor has some photos on their website to help you with the CYA test but your interpretation seems correct. You certainly don't have more than 20ppm. The rest of your post is puzzling.

1. When you had 80ppm, how did you test?

2. I would never trust a CYA test from the pool store. That 54 sounds like a computer readout from a strip. They can be further wrong than that

3. What sort of daily FC loss are you experienceing? Is it greater than 3ppm?

 

[frustratedpoolmom]

I agree, if the 80 test was pool store, disregard it and the 54.

Trust your own testing.

 

[BigBrownLog]

i had the test done at the pool store when i had 40ppm and i added enough cya to get it to 80ppm.

yeah the 54ppm was a comp. test strip i didnt realize that he did it that way so today i made him do it both ways to show him his machine is Darn! he got 30 with chem test but he did it under florecent light.

i was just really wondering if a lil rain and filling a couple inches 3-4 times would reduce it that much?

isn't it relative to the % you add.... drain half of pool fill it back up and result is 100ppm down to 50ppm?

 

[BigBrownLog]

i dont know exactly how much chlorine i loose durring the day. i have been keeping the FC at 8ppm to get rid of some algae staining from this winter. i really have not seen the FC change and i test it each day and every other night.

which is puzzeling with less than 20ppm cya

 

[duraleigh]

isn't it relative to the % you add.... drain half of pool fill it back up and result is 100ppm down to 50ppm?

That's correct

 

[Butterfly]

Here's the link to the visual for the CYA test from Taylor:

http://www.taylortechnologies.com/Chemi ... ntentID=44

 

[JasonLion]

i had the test done at the pool store when i had 40ppm and i added enough cya to get it to 80ppm.

isn't it relative to the % you add.... drain half of pool fill it back up and result is 100ppm down to 50ppm?

All you really know is that you added enough to bring it up by 40. What the pool store said should just be ignored.

The amount of CYA lost by water replacement is just the same percentage lost as the percentage of water that gets replaced. Lowering CYA by 50% takes a lot of water replacement.

But what I see in your description is that you added 40 ppm of CYA and are now getting test results near 20. That could be because the CYA you added was not 100% cyanuric acid, or because you didn't give it the full week to dissolve, or because you added it through the skimmer and then backwashed/cleaned the filter less than a week later, or your calculations about how much to add were off, or any of several other reasons.

In any case, trust the test results from the TF100.

 

[BigBrownLog]

yeah my cya came from leslies and im pretty sure it says 99.9 or 99% acid. the dry stuff. i cant remember if i vacumed within a week after i added it but that souns like the closest possible reason. thanks for all your help guys.

 

[BigBrownLog]

oh yeah it has been 6-8 weeks since i got the water straight and i still have the stains from algae. i understand that if u keep at shock levels it will go away sooner or later but it is unsightly and i want to get rid of it. is there a faster way?

 

[frustratedpoolmom]

IF the stains are organic they usually fade after a couple months of proper FC levels.

Did you confirm they are organic? One, if they are organic, they would likely vanish at shock level, only to return when the FC drops. Or, you can hold a trichlor puck on the stains and see if they fade. If that does nothing try a Vitamin C tablet on the stains to see if they are metal.

 

[BigBrownLog]

so just hold the trichlor puck there or rub it and for how long.

same question with the vitamin c pill.

 

[JasonLion]

The vitamin C tablet should have a visible effect within 30 seconds. You can leave a small vitamin C tablet longer without risk.

Trichlor can take longer, but if you leave it too long it can make a permanent mark. I would give it a minute or two and then remove it. If it is going to work there should be a visible effect by then.

 

[BigBrownLog]

ok thanks guys i wiil try that tomorrow.