CYA test

[TRazzNJ]

I just got my TF100 and my CYA levels are weird. Monday I tested with a Leslie pools DPD kit and it showed 110. Thursday I tested the TF100 kit showed 100(after I replaced 1/3 the water. I re-tested and it showed 90. I went to Leslie pool supply(OMG, they are (fill in the blank) and they said it was 45. Yesterday I tested and it was 90 so I went to Leslie's again (painful to be in there) and they told me it was 28, and I should add stabilizer. Today I tested and it was 70(about what I thought it should be after that water replacement)
Are the people at Leslie's or any other pool store just that incompetent or deceitful?? Does it take time for CYA to read lower after water replacement? Does it take some practice getting the readings right? When should I trust my testing?

Also, they said my Phosphates were 300 on Thursday and 800 on Saturday(they tried to sell me a $30 quart of Phos-free and said that Algae live on phosphates.

BTW.....Water is Crystal clear!
Other numbers are:
FC-7.5
CC-0
TC-7.5
PH-7.2
TA-80
CH-160
CYA-70
Temp-80

 

[duraleigh]

Are the people at Leslie's or any other pool store just that incompetent or deceitful?? No, they use poor methods and are frequently incompetent but I don't believe they are deceitful. (usually)

Does it take time for CYA to read lower after water replacement? No.

Does it take some practice getting the readings right? Yes. Being precise isn't absoloutely necessary. plus or minus 10 is the test accuracy and you'll vary from that a little when your new with the test.

When should I trust my testing? Right now. Your drops-based results are virtually always better than any other source.

 

[PVille]

I stopped using the pool store results two years ago. They were never as careful as I was when performing the tests and our results never matched. I use my Taylor test kit and only use my results and things are fine.

I found this article on CYA testing from the Taylor web site useful.

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

 

[PaulR]

Does it take time for CYA to read lower after water replacement? No.

Well, you need to give the fresh water time to mix in with what was left in the pool, but I figure 1/2 hour with the pump running will take care of that. (Picky, picky.)

Aside from that, ditto to everything duraleigh said.
--paulr

 

[Butterfly]

BTW, TRazzNJ , your numbers look great

Ditto on the "always trust your own testing". :-D