I have one and use one.........BUT- not all the time.
They are good if you have an algae flair up-they remove the spores.
They can also be used with good effect for a number of other things-
you should just not run one permanently. Use it as a tool to help
fight (or keep at bay), whatever your having a problem with-
then remove it. Make sure you don't get a calcium build up over
the bulb cover, this will render it useless.