I have been battling with dinoflagellates and let me tell you exactly how I beat it do not keep your nitrates at 0 try and have a little nitrate,do not do a blackout doesn't work tried it, stop all water changes, do not dose anything at all but raise your ph a little, rinse all frozen food and make sure you are not giving the dinos anything to feed on at all and slowly they will go away, water changes and all in one dosing to maintain levels are the worst thing you can do. Also I switched off my bio pellet reactor and the reason for this is because my tank was so clean it's possible the bio pellets turn into a carbon source which the Dino can feed off! Good luck my dinos aren't completely gone but they are reduced to about 10 percent to off what they were and all my corals are starting to look happy again I still haven't done a water change and will not do one until nitrate or phosphate start creeping to much or when the dinos completely goes away