Then you need to design for UV dose of 50mJ/cm^2. Most smaller UVs are advertise for clear water, it takes a very low dose for that so beware. Takes a lot more for protozoan and bacterial.
I'm thinking I might just forgo the UV filter all together since I can keep water clearer and cleaner with more water changes and those will also cost less on the monthly basis than UV. healthy fish is the first defense against disease I will take this knowledge though and setup a comprehensive quarantine setup with UV filtration. What flow rate would this filter support: http://www.fosterandsmithaquatics.com/product/prod_display.cfm?c=5163+5165+7430&pcatid=7430
the 120 watt version? What is the maximum to kill parasites and bacteria?