I'm building three good size coops for my chickens and I'm thinking that I want to have lights set up to induce laying in the shorter months of the year... My question is: What wattage would I need for the lights? Would I need a 250 watt bulb for more heat and more light or would a smaller wattage do it? I plan to run the lights with a timer for as long as I need them to compensate for a 14 hrs day. (for instance, have them turn on at 3 or 4am and off at 6am or when the sun rises) One pen will be about 12ft by 20ft and the other two will be about 7ft by 7ft. Thanks.