Unknown brown stringy growth

[prvrbs35]

Hello,
I am new to this forum. I have had a Red Sea 130 for almost 4 years. I purchased used and was thriving until I did not have time to maintain and nearly all my coral have gone away due to lighting issues. I currently have Steve's LED retrofit in my hood. My fish survived. I started adding coral last year. However, I have this brown mesh like growth that is spreading over my rock. When I hit it with the baster it retracts. I have brushed some off with a toothbrush and it comes off connected like a mesh or spider web like pieces. I have tried search various sites and have look through many images. I have not been able to identify this growth. What would be the best way to stop the spread?
I also believe I have acquired different species of aiptasia. I will do more research on this and save it for another thread if need be. - Thanks

 

[mzkrista]

It's not algae they are hydroids. Very aggressive and will sting coral. I'd take the rock out and get rid of it or scrub it with peroxide and water.

 

[prvrbs35]

Thanks mzkrista,

I did not think it was algae. It does not behave like algae. It retracts/disappears into rock when basted or brushed. Unfortunately, this menace is on rock and is growing amongst the coral. At the next water change I will see what I can do to reduce some growth. Any other ideas would be appreciated.

 

[karimwassef]

kalk paste?