There are a few nutes that say they don't require CalMag but I might use it anyway. As it is I use RO water and CalMAg and love the way my plants grow.

Worst case scenario....enough magnesium, calcium deficiencies etc can certainly eventually kill your plants one way or another.
Weedhound Reviewed by Weedhound on . calmag plus how important is calmag plus if you are using distilled tap water, what effects will it have on my plant if i dont use it? Rating: 5