here is 1 thing u need to worry about with a uv and a reef. depending on your water flow threw the uv u can kill a lot of plantonic food that corals need. if u have a refugium it definately should be on a separate pump before the refugium so not to kill or hurt pods.
i do have 1 on my 30gal reef with a refugium but i only will use it for an emergency. i ran it for a few days when i got it. i noticed the water was clearer and much less dust algae on the glass. but im afraid to run it 24/7.
now on a fowlr tank i would definately use 1 . then again depends on if u run a fuge or not.
im actually having a refugium/ built as we speak for my 125 . it will be a mostly fish with some lps/soft corals, very few. i was advised to not run a uv with a refugium. he made this very clear.
after all that rambling on, if u plan on just using a basic sump/berlin u should be fine. maybe just run it for 8 hours during the daylight cycle.