There's a lot you can do to prevent it. I was able to my elevating MAG levels and dosing daily with hydrogen Peroxide.
Once you’ve removed everything you can see from the rock, bathe the areas where it was growing in 3% hydrogen peroxide for 3-4 minutes.
Remember to do this in a small container you keep outside of your tank. Most people realize they are fighting bryopsis algae right before they go crazy. This is because they thought they had hair algae and were fighting it with the traditional methods . These three steps important in keeping control :
a) Lowering nutrient loads in the tank by performing significant water changes and reducing the amount and frequency of food you add to the tank.
b) Adjusting the lights to ****** the growth of the algae by reducing the number of hours they run, shifting the spectrum towards blue, or shutting them off altogether for a few days
c) Increasing water flow to remove dead spots, keeping detritus suspended in the water and making it harder for the problem algae to get established
The big issue versus other algae is, bryopsis algae seem to be immune to conventional algae fighting methods.
The most evffective treatment is the use of Fluconazole which is also used as a prescription anti-fungal treatment
Reef Flux is a brand name aquarium medicine that contains fluconazole. Funny is, when you buy Flux, the instructions say NOT to use Reef Flux if your tank has Caulerpa or bryopsis algae–to avoid nutrient spikes. Reading between the lines there, it’s going to kill your algae and cause your water parameters to get a bit rough. Which does also make an important point about watching your water parameters to deal with any nutrient spikes.
The recommended dosage is to open and pour in 1 capsule for every 10 gallons of water. But remember, that is the recommended dose to fight a fungal infection on your fish.
To fight bryopsis, most people online report that they used 20mg per gallon–essentially 1 capsule for each gallon of water. This is a bit strong of a dose. Fluconazole is stable in saltwater and is much easier to dose than copper to fight saltwater ich. You add it to the tank once and watch it work over the next couple of weeks.
My way of fighting Bryopsis is to safely raise the magnesium levels in your tank. When raising magnesium levels in your tank, you want to raise it up to about 1400 ppm – 1600 ppm to fight bryopsis algae–and you want to do this slowly, over a period of about a week or so, to avoid shocking anything in your tank.
Keep in mind that some of the corals in your tank will also ‘consume’ magnesium, so you need a high-quality test kit to track your magnesium levels, over time, to make sure the Mg levels are in the therapeutic range.