I don't think it's a temperature problem(22 is fine) or a nitrogen deficiency as half of the leaves ate dark green and some have the burnt tip and curler means they have enough or too much nitrogen. Do you test the level of your pH? I've noticed some yellow/brown spots which could be pests invading (you should check under those leaves to make sure) or magnesium deficiency it could be... But I think more likely its a salt build up caused by pH fluctuation or no pain water flushing /feeding. Hope it helps, the other plant looks super healthy BTW, just remember growing two docent strains together, they are always going to have different needs.