cya 0 after nearly 3 1/2 lbs. stabilizer

[fullhouse]

it has been more than a week since i added 3 1/2 lbs of stabilizer i took a water sample to the pool store 2 different times today and had it tested both tests came out with 0 cya. is there any reason this should be happening. i had added the stabilizer in an old knee high tied to the ladder and it dissolved in around 2 or 3 days. i need to know if i should add more stabilizer or give this a few more days to read.

[Watermom]

What is the volume of your pool?

[fullhouse]

sorry should have posted volume. i have an ag 10,500 gallon vinyl liner.

[Watermom]

I would think you should be getting a cya reading. I'll have to go and look at my container to see what 3.5 lbs should've added to that volume. I can't remember off-hand. Somebody else may have that info in front of them and can reply. At any rate, I'd give it a few more days, just to be sure and then I'd go slow with adding a little more. Better to gradually get it where you want it than to overshoot and have the level be too high.

[Sherra]

According to the BleachCalc it should be 40-45 PPM.

[DavidD]

I'm in agreement with Sherra. I don't have any ideas what could be causing this but have had a similar experience with pool stores testing for CYA. I was in the “good” Pool Shop in town early this year getting poly etc. and had them test my water, even though I'd just tested with the Ps233. Everything was very close except the CYA. They came up with 15 ppm, I came up with 30 two times in a row. Went to a "bad" pool store that is right up the road and the professional there (17 to 18 years old and a pound of chewing gum in her mouth) came up with 10 ppm two times in a row. Now I'm perplexed. Is Ben’s kit wrong? Have I been off all these years? I then pulled out an old Pentair kit I got with the pool. It has the tablets for testing CYA. The package was in good shape so I gave it a whirl, twice. Both times tested 30+/-.
Moral of the story: Do your own test.............

[waterbear]

it has been more than a week since i added 3 1/2 lbs of stabilizer i took a water sample to the pool store 2 different times today and had it tested both tests came out with 0 cya. is there any reason this should be happening. i had added the stabilizer in an old knee high tied to the ladder and it dissolved in around 2 or 3 days. i need to know if i should add more stabilizer or give this a few more days to read.

There is a good reason the pool store would show 9 cya. They want to sell you more!

the cya test is the easiest one to do wrong. Test for it yourself!

[fullhouse]

"There is a good reason the pool store would show 9 cya. They want to sell you more!"quoted from waterbear.
waterbear you have the same idea i did. it looks like i only have enough test solution left to do the cya test one more time. (waiting on new solution in mail) tomorrow i will perform the cya test at home and check my results. hopefully there will be a higher cya level.from the amt of stabilizer i have added i think i should be in the 30-40 range.thanks for all the help.

[fullhouse]

i checked stabilizer this morning with my test kit and i show cya 20. this is more than a week after adding 3 1/2 lbs stabilizer. from reading on the bottle i think i should be up about 30-40. is it better to wait a while longer before adding more stabilizer. i have never had a chlorine pool so not really sure if sometimes it takes extra long for it to read.
ag 10,500 vinyl liner

[DavidD]

I personally would wait before adding any more CYA. At a level of 20 ppm, you should keep your FC around 2 ppm. This will give you some breathing room. Once you get your new solution, test again. In the beginning, I'd test for CYA every other week or so. It was really pointless as I was using only bleach so my CYA would never really rise. I now only test it a week or so after using trichlor pucks (if I've been gone for a week or longer) and at the beginning and end of each season.