the plants will burn if too close to the light at 90 but thats because of how hot the light is if you plan on growing you might want to think about having smaller sized plants say 12inches when you put them into flowering and devide your closet into 2 seperate spaces you only need a vegetative room of about 2 feet and a flowering room of about 3feet to 3 and a half i get a yeild of about 3 pounds with this system peace