Yes .12 ppm phosphates is high. If you are running a fish only, it is only an issue if you have algae blooms. I doubt that soft corals would care and maybe LPS corals wouldn’t either. However SPS corals probably would not like it.
You could run some GFO. Be really careful. A little GFO goes a long way. And it absorbs the phosphates really fast.
When I get high phosphates (not often), I run about a tablespoon or two of GFO on a 300 gallon and that knocks it right back. But what I consider ”high” is far lower than what you have. I rinse the GFO in RODI (It has all sorts of dust) and put it in a small filter sock and stick it into a high flow area in the sump but usually I just toss it into my big filter sock. A reactor is probably better but this works.