Looks like Potassium is pretty easy to test for, levels around 400 ppm should be ok. But Sodium based Nitrate and Phosphate powders are easy to find and cheap too.
A Potassium test kit might be a good thing to have anyway.
Thanks, Randy, never really thought about Potassium build-up.
A Potassium test kit might be a good thing to have anyway.
Thanks, Randy, never really thought about Potassium build-up.