Looks to be prorocentrum dinos. They are pretty toxic, right next to ostreopsis. They do not go into the water column regularly like ostreopsis. A blackout will force them to move into the water column though. I recommend the following:
Get a UV, even the cheap Green killing machine will work
Dose as many pods as you can get your hands on
Live phyto is your friend.
NO coral foods whatsoever, no aminos no nothing.
Dose microbacter 7 or similar product daily
Dose 1ml 3% peroxide per gallon daily
lower photo period to no longer than 4-5 hours a day.
Dose nitrates if you have to, try to keep at 5ppm a day at a minmum.
Dose phosphate if you have to, try to keep at .1-.5