In this article I have partnered with our team member Todd in which we will be discussing the algae know as bryopsis. Much like other micro algae, this one is also considered a nuisance algae.  Most, if not all people want it removed from their tanks so we found this to be a very important topic to discuss for everyone in the aquarium hobby. Our research will also help you prevent this pest from spreading, as well as looking for signs for possible outbreak. Below is a list in Q&A format on the most popular questions about this algae.


What is Bryopsis?

“Bryopsis is a photosynthetic in the family of bryopsidaceae it grows in a fern like pattern and a variation of colors.”



Does Bryopsis get introduced into an aquarium differently than other types of algae?

“Bryopsis is introduced in the typical manner as green hair algae. It is most common to introduce Bryopsis from frag plugs and the addition of live rock.”



Aside from Bryopsis being considered a hair algae, are there any other notable differences in its cellular structure?

“Its identification resembles a delicate branching fern structure similar to outdoor ferns with thick trunks.

It typically is rooted solid within the structure attached to. It feeds off of both photosynthesis and available organics.

It tends to grow larger than common hair algae both vertically and horizontally than the typical hair algae.”


bryopsis magnified


What is the best method of removing bryopsis from an aquarium?

“Nutrient control and manual removal is the common method but through extensive testing H2O2 is becoming a popular way to eradicate Bryopsis from being introduced to a tank and to treat the infested areas.

The best method for any Bryopsis growth is to apply 3% hydrogen peroxide directly to the growth area outside the tank. Let the hydrogen peroxide sit for 3 to 4 minutes on the affected area then reintroduce to the tank.  The Bryopsis will be clear or gone within 72 hours.”



How quickly does it spread when established in an aquarium setting?

“The spread of this algae can be rapid with available lighting, nutrients and organics to the roots and branches.

Also this depends on the tank itself. With proper husbandry this will minimize how fast it can spread. Also lighting plays a big part in the bryopsis growth as well. The more available light and the more nutrients in the system, means the faster it will grow and spread.”



Bryopsis usually leeches onto rocks. Can it also leech onto coral and spread in a similar manner as well?

“Yes it can leech onto frag plugs, LPS exposed branches and substrate. This will also take hold onto the sides of equipment.”




How common is it to occur in one’s aquarium?

“It is common to introduce Bryopsis going unrecognized on or with additions to the tank.

It is also most common to new tanks as live rock is added initially to set a tank up. This is one of the largest Bryopsis harboring introductions to the reef aquaria.”



Are there any other facts we should know about Bryopsis in terms of treatment and removal?

“We all must keep in mind this one fact about this algae removal.

If manual removal is preformed and the roots are left in place then the Bryopsis plant itself will continue to survive.

The only option I have found is the hydrogen peroxide application to the root system.”