Need help what is this?

[Firefish17]

Can anyone tell me what the purplish stuff on my live rock is as well as the little white things sticking out of it? There are a few of these purple patches on my rock. Additionally do I need to do anything about it? My tank is a fowlr that has been running around a year. All if my live rock is green from green coraline algae I would sure like to see it turn purple.

Thanks

 

[vetteguy53081]

Can anyone tell me what the purplish stuff on my live rock is as well as the little white things sticking out of it? There are a few of these purple patches on my rock. Additionally do I need to do anything about it? My tank is a fowlr that has been running around a year. All if my live rock is green from green coraline algae I would sure like to see it turn purple.

Thanks

Colonial hydroids. Theyre multiplying due to food supply. Starve them and theyll diminish. They favor brine shrimp.
Direct water flow towards them, Not at them and they will be unable to grab food and starve