kh reading high

[Aquarium_Medics]

I did the tests on his tank and at first couldn't believe that it was that high and tested again. I know the test kit is good as it was bought about 2 months ago and i get typical test results on my tanks and those of my clients. I did ask about his RO/DI filter and was told he had to change the DI insert.

I didn't think about it at the time but next visit, i'll test the ro/di filter output.