New to pools, testing mineral pool

[Lee2020]

I was recently in contact with Clear Choice Labs (Pooltest suppliers in Australia like Taylor’s) about my Maytronics Dead Sea mineral system. They pointed me to the fact that their tests May not work with my system due to the variance in minerals. They told me that the calcium hardness test is usually the one they have problems with and I could get a small test and try.
Being that I would have to compare it to something I went to the four pool shops in my area to see if there was some consistencies and here are the results
with vast differences in CH. 3 of them using lamotte systems which Clear Choice indicated would be a good start. The one at the high end (1800) said it was due to the magnesium content, they done a magnesium strip test which said it was high also... what do I do for testing with such differences in CH?
To start this adventure I need to get a test kit, so what do I do?

 

[ajw22]

Welcome to TFP.

You can read about the limitations of the LaMotte systems here - Pool Test Kits - Further Reading

Here is a thread about testing with magnesium interference...

Ch test precipitate

Ive always had some sort of precipitate form when doing the CH test. Usually the precipitate and solution both turn colors at the same time. On this test the solution turned blue but the precipitate stayed bright pink. I added a number of reagent drops after the solution was blue and the...

www.troublefreepool.com

We don’t recommend using those mineral systems.