Sorry for not answering the light question. I use a Mega ray 100watt SB.... never had a problem. I think 160 watt for a 55 gal. breeder may be to hot. I used a 100 watt sb in a 40 gal. breeder at the required distance 15 inch and the temp was running to hot 135* basking 100*cool side. What is the size of your cage and the basking spot distance.