Distilled & Cal-Mag Plus

I'm about to start a grow and I am going to be using distilled water and cal-mag plus. I'm wondering if I should just start with the bottles feeding schedule? When in the plants like should I start giving cal-mag? Beginning of life or after seedling stage?

Plants don't need nutes till they get their first set of true leaves. After that start at 1/4 the recomended feeding and see what the plant takes up.. If you're in soils that's as far as my knowlage goes