That is one of the problems with these "grow guides". (most definatelly NOT a Bible) They don't fully explain, and you can't ask questions.

The outdoor grow and street lamp analogy has been around for many years, but has little to do with us indoor growers. The sun delivers...what...a trillion lumens per square foot? (from every angle possible...reflected light) And a streetlamp at 20 feet (or so) might be a 100w per sq.ft. (numbers fudged to approximate true knowledge) That great difference is what...a couple-o-billion:1 ratio of daylight to darkness interference. Would be like a 1000w light user worrying about a candle at 100 yards.

Climb-in, shut the door, and wait a couple of minutes till your eyes adjust. If you see any light...best to fix the problem. You might be able to get away with the stress of an indicator light or small light leak once in a while, but if it's not the only source of stress, problems will likely be a guarantee.
Rusty Trichome Reviewed by Rusty Trichome on . Intake/lightleak question :wtf:hi everyone,i've built a growroom in the back of my shed,i have a 6"fan for extraction and 2 x 1.2m lenghts of 4"pipe that i want to use for air intake(pulling air from rest of shed).my Q is...if its daylight outside and my light is off,how do i stop light leeking down the pipes and messing things up!!please help,i need to know before i cut 4"holes i dont need,thanx!:jointsmile: Rating: 5