cool setup, It appears from your pictures that the burn you are seeing is from nutrients, ease up on the plant food. every 4 days is a bit much IMO.
also if you setup your fan to blow right over the canopy aimed 1/2 way between your lights it will help to disburse the heat before it reaches your canopy and break it up a bit.
some times I will cut the tips off that start to burn, this hasn't done any harm. or just leave them.
growdemon Reviewed by growdemon on . RE: My First Grow - want to do it right, but dont want to buy more than i need either hey everyone, i have already read a few posts and have not found answers to all my questions but am impressed with the responses everyone has gave, very positive and helpful. anyway this will be be my very first grow, and was reading some stuff on a closet grow setup, but i am actually planning on using a bathroom. Still a little confused with the lighting requirements, whether it is dependent on the total size of the room, or just the size of the table that contains the plants. Well Rating: 5