A PH of 8.2 is a little high. When adding chemicals other than chlorine it is often best to use less than you really think you need. Then you can test the water and see how you are doing and adjust how much you add for the second dose.
You can increase the range of the OTO test by diluting the pool water 1 to 1 with distilled water and then doubling the result. If you need to go higher still you can add two parts of distilled water to one of pool water and multiply the result by three. The results will be a bit less accurate but usable.
You can increase the range of the OTO test by diluting the pool water 1 to 1 with distilled water and then doubling the result. If you need to go higher still you can add two parts of distilled water to one of pool water and multiply the result by three. The results will be a bit less accurate but usable.