The 125G is just over a year now. Here's a FTS of the reef at 12 months.
Being sps dominant, stable water parameters are a must. Ample light and flow too.
I try to keep things as simple as possible. I run the Balling method and auto dose the major and minor elements. Aside from that, I have filter wool replaced weekly in acrylic sock holders, a large protein skimmer, and a refugium with chaeto that I prune monthly. There's a small 13W UV pump in the sump as well. 10% weekly water changes.
I introduced beneficial bacteria from the start to get the tank seeded and cycled. Regular dosing (every other week) of bacteria helps to keep nitrates and phosphates in check too, especially when bioload is elevated.
Auto water top-up is gravity fed and controlled with a float valve.
Fish are fed a pellets, flake, freeze-dried black worms and/or nori once or twice daily.
Corals get amino acids.