You still haven't really provided enough info!!
What size pots as Racerx asked?
What is your air flow like? Do you circulate the same stale air with an oscillating fan? Is the grow space sealed with no fresh air intake?
Do you have a Max/Min Hygrometer to see if temperature goes higher of lower that the reading you get when you go take a peek? Got no pics? What strain (could be low-rider)? Professional soil or B&Q? Growing from seed?
SpiritLevel Reviewed by SpiritLevel on . Yo Geezers Any Hints? Yo wassup, im growing my first Bolton Budhead but its not growing very fast, i have given it plenty of nutrients and plenty of light (400watt HPS) but it still wont grow any bigger. Any ideas guys? Rating: 5