FHs are a combination of Amphilophus trimaculatus and something else (maybe Vieja).
These cichlids come from rivers, and flowing streams, and although these waters would not be a rapids type flow, I doubt the flow from your UV would be a bother. A few rocks and caves for spaces to rest, should be enough.
In my trimac tanks I used flows if 500 gallons per hour (1800 +Lph), in 6 ft tanks.