Since repotting in medium sized pots and treating with epsom salts problem seems to have stopped. Though growth has been slow they seem to be picking up now. The more I read the more I am convinced the problem was Mg deficiency as ph is ok at 6.5. I live in a small town in the middle of nowhere...
Tested ph of soil, 6.5 so don't think any problem there. Repotted in new soil also 6.5. A little rootbound but not too bad. Gave them a mild dose of epsom salts after reading nutrient disorder problem solver by jackerspackle as margins of leaves turned up and leaves yellowing but veins green...
Plants are about 20 inches from lights. My concern is too much fertiliser rather than lack of since I have fed regularly. Have not tested ph so will try get a test kit today.
Got 3 fruit spirit plants about 5 weeks old grown from feminised seed. Still in original seed raising mix. Indoors, 600w, temp 18-30 degrees C, humidity 35-70. Using rain water collected off roof and general store bought organic liquid fertiliser, foliar and in soil. Want to repot but not sure...