Zandor don't forget lumens are decreased at an exponantial rate the further the light is away from the plants. As a general rule of thumb cannabis likes the same tempature we do. To be exact the range for good growth is between 65f and 85f with 75f being optimal sometimes just a little warmer will speed growth somewhat. But going over 85f will most certainly stunt growth unless you are implementing CO2 which if that is the case you can sucsessfully raise the tempatures to around 90f and 95f for a longer period of time as long as you are giving the plants CO2 at regular intervals. To make it simple to see if you think the light is too close to your plants place your hand just over the top of your plants for about one minuite and if you cant take the heat neither can they. I personally have a 400watt HPS system and I distance my light away from my plants 18 inches and I get superior growth although I do use 2 mil thick mylar to recover lumens that would otherwise be lost. If you have to use fluro's use cool white tubes for vegatative growth and warm white for flowering. Fluro's must be no further than 2 inches away from the tops of the plants to receive optimal lumen coverage.This is bare bones but the minimum amount of lumens per square foot should never be less than 200 and buds grown under fluros are always small light airy and not very potent. good luck.
Zero Revolt Reviewed by Zero Revolt on . lumens how many lumens would i need for my grow room my grow room is small and only growing one plant, im still researching a fluro for cheap i can purchase at ace hard ware or home depot and also what color white or blue Rating: 5