Fluconazole 200MG -
https://www.payless-petproducts.com/fluconazole200.html
Same as Reef HD/Flux and much cheaper. Buy extra so you have it if you need to treat again later, I have done it and is very effective.
- 200MG per 10 gallons, just open the capsules mix it with a cup of your tank water and throw it in the tank.
Remember to remove skimmer cup (leave it running and let if overflow to keep water oxygenated), remove any carbon media and no water changes doing treatment (unless in an emergency) Do this for a couple of weeks.
If you don't notice the bryopsis turning white and dying, you do another half dose or a full one again and leave it longer.
I've done this treatment twice, and it really works. Some bryopsis patches are a little harder to dye, so I dosed more. No side effects I noticed, snails, pods, inverts, fish and corals always stayed healthy.
As a little tip, I would do a BIG WATER CHANGE before starting treatment since you won't be skimming or using anything to remove nitrates for the duration of the treatment.
Good luck man, bryopsis sucks! Thank God we found Fluconazole