Second week of flower should I fertilzer

Don't defoliate. More leaves = more energy being made = more potential growth. Buds do not need direct exposure to light to grow, they need the leaves to make the energy they need to grow. Without a diary and knowing what you have or have not been doing or fertilizing, it is impossible to give advice about feeding. But generally yes, now is the time to move towards "bloom" fertilizers.

Yeah, you have some visible issues.. chlorosis around serated tips, paling from inside out on top-most leaves. Could be too little K and S, respectively, or maybe something is too high and locking them out. While you have to ramp up from seedling to mature vege and maybe shift a little bit heading into flower, consistency is what you want.. consistently fertilizing without causing deficiency nor toxicity. If in soil, knowing what you have to add to the mix as a particular soil amendment is exhausted, etc etc.. but it adds up to maintaining a healthy concentration and ratio of nutrients around the roots. This is the best way to feed. Turns out it's less about the ratio of use and more about ratio to remain readily available. Active transport is a good chunk of what enters the plant, especially for P & K.

Always