Unless you see some buges or mites I don't think you have much of a problem. Some strains seem to have this trait. The leaves start out looking good and then develope spots . I first saw it on orange bud and it didn't affect the plants at all they are in budding stage week 6. Look for my name in the hydro section. My first grow of northern lights no spots , I am now growing papaya for mothers and they have the same spots. Doesn't matter if the lights are flouro's, HPS or MH same spots. The plants are thriving so I'm not going to worry over it.