First timers

Not a good week. The lower fan leaves on one of the girls started yellowing and a few blotches on them, too. What I have identified is: 1. My pH meter was off. Must re-calibrate it regularly. 2. I was underwatering significantly. When the good lady came back the things were dry. I suspect any feed was not getting to the roots and was causing hot spots. 3. These three girls had pretty much no cal-mag for four weeks as seedlings. We used filtered water and no feed and also the compost medium was low in minerals. Anyway, put some Epsom salts on as it can't do any harm. Holding off on the feed until watering has stabilised. What buds there are are getting nice and crystalline.