Confused about CYA readings

[ElkPool]

I have one of the good test kits, and strips also, although both were purchased about a year ago.

My CYA consistently tested high last year (80-100), but I made do, and every day I swam I tried to dump out at least a hundred buckets of water. I had to refill for a while upon opening.

My first test of the water (with the good test kit) showed negligible CYA. Because of that, I put in two pounds of pool store shock, which I bought before discovering this site and had avoided because of the CYA issue.

A few hours later, I checked the water again. CYA of 100 according to the good test kit...then I used a strip, and the strip showed it to be in the good range.

Does anyone know what might be causing these wildly fluctuating results? The test kits have been stored in a cool, dark place.

Right now my FC is ~ 5 and my CC is ~ 1.5. How should I continue to shock the pool?

Thanks in advance!

 

[duraleigh]

The CYA test is not particularly precise but it is pretty repeatable.....I think you have some kind of testing error taking place.

The strips are likely out of date and pretty worthless. Describe how you are performing the CYA test and with what kit.

 

[ElkPool]

OK, now I'm REALLY confused. A couple hours later, I just tested two different samples and got ~50 each time.

I have the Leslie's K-2006 with all the Taylor chemicals. Fill the little bottle with 7ml of pool water, 7ml of the solution, shake for 30 seconds and pour until the black dot goes away.

 

[duraleigh]

Chalk it up to one of those "Twilight Zone" things and go with 50ppm :lol: