I don't have specific experience with the Jebo UV sterilizer, but I do use a UV sterlizer on my reef...it's operating on the sump. All UV sterilizers work on the same basic principle, though. In a nutshell....water from the tank or sump goes in and passes over the UV bulb within a particular waterflow range ("dwell-time" which is generally measured in gph or gallons per hour)...If it isn't in that range...say, faster, for example....any unwanted organisms like parasites or algae that pass through it won't be exposed to the killing quality of the UV bulb for a long enough time to be killed.
So, it's critical that you match up the sterilizer that you get with a waterpump that pumps the water within the "dwell-time" rate that's recommended by the manufacturer. (remember to consider the "head loss" to the pump's actual flow rate that's the result of your plumbing configuration.) The manufacturer will tell you the proper "dwell-time" for killing algae, which would be one rate, and for killing algae and pathogens, which would be at a slower rate.
Be aware, nick, that a UV sterilizer isn't a guarantee that your fish will be protected completely. With all of the hidden, protected places in a reef with its live rock, not all of the pathogens will pass through the UV sterilizer and some can attach to a fish before being killed by it. Still, as I said, I do use one as another method of raising the odds in my fishes's favor.