when they got there 6 set of leaves i started spraying once a day then the next week twice a day an so on i would be careful some strains dont take well to that high of a concentrated growth hormone so go at a slow pace ive had this one strain black domina that just loved the stuff and this bubbleberry strain i was growing could only handle it once a week so like i said take it slow and get to know what your plants like the best good luck and nice growing:thumbsup: