My Oct X-160 took quite a while to break in. Well over a month. Until a few days ago, I had no fish in my 70G and I always produced a little bit of dark green skimmate. With 10 fish, something isn't right...
As a side note, a better option over mesh modding may be an upgraded pinwheel, especially for such a large tank.
The current hot pin wheel is the Warner Marine Red Demon:
The Purple Pinwheel is also Popular: