I use Emperor Aquatics UV for my pond... very happy with it. I bought one for my saltwater tank, but not setup yet. If you need one, contact a guy in Oceanside, he listed his items on craigslist. Very nice guy to deal with and he has the best price.
http://sandiego.craigslist.org/nsd/for/2718980044.html
... and he has all kind of pvc reducers, valves etc that you can't find from the local stores... all of his fittings are schedule 80 vs. schedule 40.