Your ferns are showing signs of cold...look at the leafs from the center,,,,they are they youngest and will tell you the general condition of the plant.

Your MJ plants are growing at a severly retarded rate due to the cold. The veins of purple are the first indicators of temp problems. You can wrap a giant blanket of 55 gallon trash bags around the plant / light to trap heat from the light.

Or, turn on one of the small mini heaters available from hardware stores. You need to warm it up badly.

At this rate, you might be ready for harvest by fall.....2006

That is simply too cold. The flower pistels would die and thin at those temps non stop. Trust me, I learned.