Im growing in canna coco 250w hps following cannas grow chart, im 3 weeks into flower. Some of my leaves are getting like brown orange spots ? Some of the leaves have a tint of purle/brown dead spots aswell. i put my Ph in at 5.8 but the runoff comes out at 5.3 is this normal im a first time coco grower. I always water till 20% runoff could anyone think what i should and can do to stop this. Also afe them flower s doing ok for 3 weeks ? I left my MH light on for first 2 weeks after flip. Thanks i will add more photos of the problem later today when lights come on