UV sterilizers are not a gimmick. They may not work as well for some folks and then do a great job for others. That just depends on how the system is set up.

UV sterilizers can provide cleaner looking water due to a decrease in free floating algae spores.

UV sterilizers can and will kill some water borne bacteria. However, the amount of bacteria that would be "sterilized" is infinitesimally tiny in regards to your eco balance. Your Nitrosomonas and Nitrobacter colonize on the surface area in the tank. rock, substrate and even the glass (to an extent). these are your two main nitrifying bacterias. They are not affected in any measurable way that I've heard of or read.

So, in summation, Hook up your UV to a low flow pump and enjoy!

-Ben