I have a 60w (9W) LED bulb in my 63 sq. ft. coop mostly so I can see to count them when locking them up for the night. It is enough light to "read a newspaper by" as others have suggested. I see two different bulbs available, "soft white" and "daylight". I prefer the "daylight", seems brighter but is one of them better than the other for the chickens? Does either of them help with egg production or are they both the wrong light frequency?