First Grow-Double Grape Auto - Mephisto

Everything was going smooth this week up until about half way through and noticed one of my plants had a nutrient deficiency. Upon further investigation/research I found out it was a CalMag deficiency. I should've taken more notes with my growdot research it turns out they fade out after week 8 so it would only make sense some kinda deficiency would pop up. Too close to flower to try and fix it with amendments so just gonna give her straight water until it's time to chop. Someone had recommended Epsom salt and water a few days after the fact but being a new grower just gonna let it go and make a mental note of it for next grow.