Hi toematoe, I am growing in the same hydro system (I don't have the cabinet. I'm using a small tent.) with LED and having the same problem. I too am up to a full dose of Magical and 50% on the rest of the Technaflora Recipe For Success. I am spraying the plants with the same solution I have in the res and I think it's helping. I am at the end of week 5 and although the spots look like shit the plants are growing like mad. So I am hoping that the spots are just ugly and don't effect the grow too much. Keep up the good work. I'll let you know if I solve the spot problem.