I took a break from tanks for about 8 years. The previous reef tanks never had dinos. This stuff is a nightmare. Previously I'd pick up a few boxes of fiji rock and have an instatank. Now with the last couple tanks it seems like it really starts getting going after 6-9 months if you add a couple pieces of rock from an established tank. There's something about dry rock that sucks.Prorocentrum is the worst. I battled them twice. First time, I was successful with silica dosing. Second time it hung around even after silica dosing. I siphoned out all the sand over the course of couple of day. Did not put any of the water back in. Essentially a mini tank reset. Dinos were gone in about 10 days.
BUT Dinos started after two things: One using flux rx to control GHA and bryopsis and adding two adding Chaeto. I already was dosing after the flux RX to not let nutrients bottom out. The chaeto never grew even with detectable nutrients, but dinos did. Maybe algae barn chaeto gave me dinos...