Thank you I want disease protection, Tank has good waste control ASM skimmer , reactors and flow rate w Chemipure and polybiomarine Polyfilters stacked media.If you're just looking to manage pathogens/disease vectors then you can get by with a 25 watt UV in your return line assume you're running about a 3x turnover on return. You're looking for sufficient exposure to damage and with enough turnover (3x ish).
If you want to manage algae (includes dino) then you need less damaging exposure but at 8x turnover (because of the very high reproduction rates of some of those organisms). That will take about 1000+ gph in your case so will need a variable speed pump or two pumps to swap out and separate piping.
You can do this with one fixed speed pump but you'll need to go to 40 watt or a bit higher to ensure proper exposures for pathogens at the higher flow rates for algae and will still need the separate piping from return unless you run very high filter flow.
If UV is to be used properly and effectively, particularly on larger tanks then a separate flow path and a flow control really need to be designed from the start. However, if you're just interested in pathogen control (which is reasonable) then it's a much easier add-on and you can see significant advantages.
Edited after original post for clarification.
Notes - check the actual exposure rating on the manufactures information.