hi smoothe,i feed mine every third water,i use coco bloom by ionic,the feed mix is 7ml per litre an i give them 500ml at a time,mine are in 10 litre pot's.not sure what to say about your feed it should have instructions on it,if not go a buy some that has!!!better to be on the safe side..the leaves dieing on the bottom is quite normal as the light only penatrate's the first 15-18",mine don't as much because of the reflective white mylar on the wall's this really helps the light bounce about...hope this helps..love an rrespect..spliffbuilder.