Does anyone have any ideas about how to reduce GH without affecting
the PH? I have too much Calcium and Magnesium in my tap water and
would like to reduce it without compromising the PH levels. My GH
right now is 10deg, which is roughly 180-200ppm. I think this is too
high and it is also affecting my plants as high concentrations of
Magnesium/ GH block the uptake of Potassium (the reason my plants are
yellowing in an otherwise healthy tank.)

Thanks in advance,
Nick D.