i just reread your last post, i'm thinkin ph problems causing various nute lock-outs. if you've never tested the ph then you don't even know what the ph of the nute solution you're watering with. to avoid ph problems, i use 1-2 tsp dolimitic lime per gall of soil and i also adjust the ph of water and nutes to the low 6's before giving anything to the plants. you also should let your pots dry out almost completely before watering. overwatering could also be a problem. i'm just trying to think of possibilities for you to look into.