Dinos are a real pain. I dealt with them for 3 months in both of my tanks. They killed several of my acropora colonies before I got them to go away.
There are a few things that I did that I think helped:
1) I reduced my nitrates to about 5 ppm. I used carbon dosing (RedSea NoPox) to do it. I don't recommend bringing your nitrates down below 5 ppm with NoPox, since you can crash your tank if you let them get too low and then continue dosing. If you have a refugium, then some macroalgae would be a good option.
2) Add a UV sterilizer. American Aquarium Products on this forum sells some nice ones. UV sterilizers really seem to help, but only if you get a good one.
3) A clean-up crew of Fighting Conchs will help somewhat. These and other conchs are the only inverts that I know that will eat the stuff. They also will eat cyanobacteria, which is really remarkable! I have groups of 5 in each of my 66 gallon tanks, and they are doing really well.
4) Having good flow helps, but I don't think it is as important as the above things that I did. I added a Gyre to one of my tanks, but I don't think that did too much.
5) I tried dosing peroxide, but that didn't seem to do too much for me, and it seemed like it was stressing my corals.
Good luck!