Hey, I know you asked this to Lija but she is not on the forum so thought I would give an answer to your question and help out. Yes the 100 watt will be ok, especially if you still have that little 7 watt matt on the side. If you get it to hit a steady 82f to 83f during the day that's perfect, and I don't think your going to have any problems doing that when your new equipment comes in.