There is a lot written about this and it's called ODNO ( over driven normal output) which means that the bulb will shine much brighter but for a shorter period of time. It also some what changes the light spectrum of the bulb as it is now really pushing those gas electrons around. Look it up on google, type in ODNO and you can read what others have done to this end , mostly on the fresh water side but I have 2 39w bulbs driven at 65w on the refuge and they are a lot brighter . I think they also cause me to fall into black holes in my sleep and travel where no man has gone before!!!!!!