Sorry for the long winded reply but need to provide some background info.
Due to a very long battle with dinos in my display tank, I was pulling the remaining corals and testing some dips to see if I could kill the dinos on the corals prior to moving them to another tank.
I identified at least 5 different types of dinos in my tank with a microscope: Ostreopsis, Coolia, Prorocentrum and 2 different species of amphidinium.
Corals were a mix of sps (acros), lps and zoas.
First batch I performed a low salinity dip (1.010 sg) for 30 seconds followed by diluted peroxide dip (8 parts water to 1 part 3% peroxide) followed by a rinse in fresh saltwater.
After dipping I monitored and found no living Ostreopsis, Prorocentrum or Coolia but did find encysted Coolia, which I assume were still viable, and active amphidinium.
A week later I followed up with another low salinity dip (1.008 sg this time) and 4:1 water to peroxide dip. Had same results as first time.
Second batch of corals which included acros, a tiny piece of monti and lps. I went straight to the 1.008 sg dip and 4:1 water/peroxide dip but used aggressive basting on the corals during the dip. Still found the amphidinium after but nothing else.
No coral losses on the first batch but lost 2 acro frags from second batch. Both had significant tissue loss before the dip so no real surprise they RTNed on me.
Low salinity dips seems to be effective on the more toxic armored dinoflagellates but won't do anything for amphidinium (from my experience only)
This may help you out in the short term but QT for your corals is best long term strategy along with a cheap microscope to confirm the presence or absence of dinos.
If dinos are encysted, there is nothing we can dip our corals in that would kill the cysts and not kill the corals.
