Re: thoughts on bio-active cya reducer
I figure your CYA level is over 500. Here is a good double check: fill the view tube with pool water (no reagent, just pool water). If you have trouble seeing the black dot, or can't see it at all, then something is up with your pool water and the CYA test isn't going to work correctly. Otherwise you are doing everything correctly and CYA is probably over 500.
None of the CYA tests are especially accurate when CYA is over 100. I can easily imagine that the pool store test and your test strips showed 150ish for a level that was actually over 500.
Here is one more double check. Try mixing 1 oz of pool water with 9 oz of tap water and doing the CYA test on that. If you still loose the black dot instantly I will be much more inclined to suspect some kind of interference I have never heard of before.
I figure your CYA level is over 500. Here is a good double check: fill the view tube with pool water (no reagent, just pool water). If you have trouble seeing the black dot, or can't see it at all, then something is up with your pool water and the CYA test isn't going to work correctly. Otherwise you are doing everything correctly and CYA is probably over 500.
None of the CYA tests are especially accurate when CYA is over 100. I can easily imagine that the pool store test and your test strips showed 150ish for a level that was actually over 500.
Here is one more double check. Try mixing 1 oz of pool water with 9 oz of tap water and doing the CYA test on that. If you still loose the black dot instantly I will be much more inclined to suspect some kind of interference I have never heard of before.