Is there such a thing as too much light?

Yes & no. If you have so much light in your grow room that you cannot keep the temperature around 75°, then you have too much light. It is like when you go outside & it is 90° outside you just want to die, plants are the same way. Anything above 80° seriously hurts your yield. As long as you keep your room around 75°, there is no such thing as too much light. Some customers go with a 1000 watt light in a 2 foot x 2 foot area, BUT you have to keep it at 75°.