Yoz... i think you're being too over critical of your grow, we ALL get these problems, very rarely do you have a grow where a couple of plants, or in fact all of them suffer one way or another, we are growing in an artificial environment and it only takes the smallest thing to upset the whole system. Next grow i would follow what you did in your first grow to the letter, but i wouldn't start again, just ride it out...learn by what ever intervention you try, be it less feed, more feed and watch the plants and see how they react. Good luck brother.