....or the old forbidden product: AZ NO3. I am guilty. i tried everything and my nitrates stayed at 20 at one point...nothing lower than that.
Then, I treated with AZ NO3 and now I've been zero nitrates for 4 months now. healthy corals. Healthy fish. Dark skimming. And I don't have a sump, wet/dry, nor a fuge.
But you might want that to be the last resort. If you can afford fuge, then maybe you should go that route.
Good luck.