I fought through bryopsis for 3-5 months. Its a challenge but is managable. Kent Tech M magnesium is what I was directed as the only magnesium supplement to help (also is suggested by vivid aquariums). From what I had researched during my struggle with bryopsis is the crucial need for maintaining proper calcium, alkalinity, and magnesium levels as well as manual removal as much as possible. I use the BRS 2 part calcium and alkalinity, along with the Kent Tech M magnesium when combating bryopsis. Raise your calcium to 460-480 ppm, alkalinity to 10-11 dkh, and magnesium to at least 1600 ppm (but with Kent Tech M magnesium) and maintain those levels best as you possibly can. It really is crucial to maintain steady levels as bryopsis tends to show up when your foundational elements are out of wack. I used my forceps to help pull it out easier and to rip it up from as much of the base of the algae as possible. For the first 6-8 weeks I was pulling it out in huge clumps almost twice a week. It will be quite a frustrating battle, but consistency will give proven results of success, as well as really dialing in on dosing, and will even have massive coral growth by the time it's gone. Its almost a win-win situation when you maintain the consistency.