Right on brutha. That is exactly the point.

One clarification is that the nutes for hard water are actually labelled for hard water use. It will say right on the bottle. The 'default' nutrient is made to be used with 'average' tap water. I, for one, have the good luck to be able to use my city water out of the tap, even in hydro, but the bad luck to have to add calmag to my well water, which is quite 'soft', even in soil! haha ... what a PITA!
But a techincally oriented grower will tell you that he likes to start with NOTHING and add only KNOWN fertilizer components to his water.

Even in dirt, you still need calmag if you use RO, distilled, or rain water. And you MUST adjust the pH of rain water, after adding the calmag, and before use on your plants.
stinkyattic Reviewed by stinkyattic on . If you use RO or distilled water you NEED CalMag Plus That's all. My fingers were cramping from typing it n times a day. Rating: 5