My test results vs. Pool Store...now what??

[waterbear]

I believe that anything above 10 ppm will cause interferance. The Taylor kit and Ben's kit might be 15 ppm. Gotta research that to get a more definative answer. Bottom line is the chlorine needs to be in the right place before you do the other testing. pH test has the same type of problem but it will show a bogus high pH when the chlorine levels are high.

[geordie]

I had the same problem last year with the Aquachem kit. In fact, I had the problem with two different Aquachem kits last summer. I was able to rely on my TA and the chlorine-ph tests were fine, but the hardness test was invalid. To begin with, it never really turned blue, and it definitely didn't turn anything other than progressively clearer. The kicker is my chlorine was 3-5, right where it needed to be for my CYA.

I assumed I had botched the tests. I KNOW I have hard water... no doubt. I've also been doing this for so many years I was positive my chlorine readings were valid. Since my hardness isn't really relevant in my pool I didn't obsess over it, but every now and then would re-test just because it bugged me! I bought a new test kit, and had the same problem.

This year at start up I wound up getting the HTH kit because it was the only game in town (aside from Ben's which I've never ordered because I manage okay without it) and suddenly, I had measurable hardness and the test worked perfectly.

If you know anyone around with a pool and a kit, get them to run a test for you.