Time for this long time alpha male to take a break from the beatings. I’ve moved him out of the group until his fins heal up, then I’ll reintroduce him to the colony after I rearrange the tank a bit. This keeps the new kid on the block from being picked on, as it’s pretty much a free for all when you change up their territories. Until the hierarchy is reset.
I usually perform large water changes, up to 90% every two to three weeks. The Tropheus just love the fresh water! They’ll surf in the current, and brighten up. If you have a seasoned tank, don’t be afraid to change more than half the water every change.