That has not been my experience, has it finally calmed down now? I would probably first pull it out and and give it a cleaning to make sure there isnt any restriction on the pump or airline. Are you doing any sort of organic carbon (vinegar, vodka?)
Question: normally we see dinos in tanks that are so low in nutrients the dinos can out compete the algaes, do you have bryopsis AND dinos? I I'm not positive on the UV affecting the medication specifically but I personally would go the other direction. Treat the bryopsis first as you may see the dinos appear again after the algae is gone.
Unrelated, there seems to be a correlation between some UV setups and high antimony, seems to be leeching from the impeller shafts or other areas. There isnt a known issue with antimony in reef tanks but with the proliferation of ICP testing we're seeing it alot more.
You dont need a specific brand of anything, but I would be weary of that product only because they dont list any other active ingredients on the website, given that products intended usage I wouldnt be surprised if there were other components that might not be as desirable in your water. I'm guessing you are in Canada? Check with BRS, see if they'll ship
this to you.
Two reasons:
1. You'll see most of the algae die off, that could increase the nutrients in your tank to an undesirable level.
2. The efficacy of this treatment is light dependent, the is a possibility that without completely cleaning the ATS it will still contain bryopsis that can "reinfect" the tank.