Cal mag

Normally, your soil and your nutes should provide the calcium the plant needs... the only time you would need to add calmag is if you start to see a calcium deficiency (small yellow/brown spots) which is NOT caused by either a nitrogen toxicity or a pH level that's not good (pH should be between 6.0 and 6.5 in soil). If a deficiency is caused by either of those two conditions, you can throw an entire bottle of calmag at the plant and it won't be able to get at it. Having calmag on hand is always a good thing but avoiding a calcium deficiency in the first place is best. So keep your pH in that range and, when you start the nutes, go really slowly. I've used FF in the past and have always had trouble with their Grow Big - always end up with a nitrogen toxicity... so start that particular nute out at 1/4 strength... and, given that you're probably not going to be starting nutes until next week (?), I would keep Grow Big at 1/4 strength for the entire grow. If, as I suspect, you're going to intro nutes next week, you can also add about 1/2 strength Big Bloom as she should be entering pre-flower by that time and it's a good idea to get her ready for flower - besides, it doesn't hurt anything. But save the Calmag in case you need it... Good luck!