my tank goes against the grain of MOST reefers in this forum, not only do i use a UV, but i also use miracle mud.... on the topic of the UV ...im so very glad i have it... i dont have any outbreaks of ich (knock on wood) ...i've introduced fish with ich (stress related)....and the ich came off within a couple days...and no other fish caught it...so im a firm believer in having it.... some people leave theres on for part of the day...and part off... leave it on 24/7 ... now it is said that it hurts good bacteria as well.... this is true.... but being honest...i cant tell ... i dont have alege outbreaks either... more importantly ...NO RED SLIME!...hehe...
best of luck to you
~chris
oh yes.... i use a rather large UV on my tank....i run a 125 ...its designed for a 190