Diagnosis help. Calcium deficiency?

@Tony Snow Yeah the low pH could be preventing some nutrients from being uptaken. I'd wait until the medium dries out before watering again to collect the PPM measurement. When you do water next, I'd water in a 6.5-6.8 pH and hope it drifts up to the ideal range.

@Mr. Grow It I was able to get the PPM of the runoff last night and it came in at ~800. Compared to the chart in your book it looks like I'm running a little high.

It's my first grow so sorry for the what may be a dumb question, but with it being high but not TOO high, would it be better to flush the soil, or just only water pH water+CalMag for the next few waterings?

@Tony Snow Some may go in a different direction that me, but I'd water in at 6.5-6.8 pH and hope it drifts up to the ideal range. If the problem doesn't get better in the mater of about 10 days, then I'd flush.