Blocking light in flowering stage

[stollhofen]

My question is , I'm using a rubbermaid grow box and when i change to the 12 and 12 light cycle should i cover the grow box in the dark cycle as i have a hole on top with the fan mounted. Thanks

 

[David Bowman]

to

During lights off in flowering, the environment must be as dark as possible as any light penetration can cause the females to hermie which will reduce the potency and yield of your harvest.