Unknown leaf burn/deficiency

[BeachWeed420]

CLERAR-EX FLUSH ADDED TO YOUR WATER WILL HELP YOU 15 MLS PER GALLON USE @ 2 Xs YOUR POT SIZE

 

[andy52]

hi,i have raed pretty much about my problem.the thing is i am into 4th week of flower and just now started having this problem.the plant is in a 3gal pot.it is 3ft tall.it is in mg soil from seed.under HPS 400w.i have never flushed the soil as i was scared of the MG deal.the plant is about 4 months old.i will add some pics after my girl gets up.the points of the leaves are starting to brown and a couple have dark spots on them.feeding ff BB,TB,and BG.full strength.thanks all