I'm growing what seems to be a very large Kali Dog in my green house. Everything has been going pretty smoothly. I had a problem with some lower leaves going a bit yellow but I think that was down to a nitrogen deficiency and I think I'm kind of on top of that. My problem now is that I've noticed a few white spots appearing on a few of the leaves, along with the odd leaf have what looks like burnt spots. I'm struggling to work out what's causing this. The plant is still growing (currently 165cm) without any problems but I'm concerned because it will start flowering in about 3 weeks and I don't want to harm my yield. I've attached some pictures, any advice would be greatly appreciated.