Hydroid?

[m3drver]

Is this a hydroid or some sort of feather duster? Theres a cluster of about 5. the pic shows the larger one with its appendages flowing in the current. If its too hard to see I will post a larger pic if i can.

Also in this pic are some leafy looking plants. Algae? Sargassum?

 

[Sadielynn]

Looks like hydroids to me .. I would say remove the rock and use a stiff (new) brush scrub off rinse in fresh salt water or diffrent water than what you scrubed them off in and replace in to tank...

 

[Kurt_Nelson]

Yup. Hydroids. Not the end of the world though - I've had ones just like that in my tank for a year. They do spread, but if you spackle them over with a paste mixture of Kalkwasser and saltwater, they'll die.

Agree with Sadielynn if the rock is able to be removed. That will also take care, possibly, of the algae that's going on.

Looks like some cute pink sponges though under that little overhang near the bottom center of the picture.

 

[m3drver]

I took care of those Hydroids today. Pulled the rock out, scrubbed it in SW, then rinsed it in fresh SW and put back in the tank. Thanks for the tip!

Kurt yeah those nice pink things are sponges huh. cool. I have a few spots on various rocks with the same thing. and they've been spreading too.

 

[Sadielynn]

They may return however they will come and go as the nutrients allow they are clonial hydroids and can sting corals ... I had/have a few that I took off with corals on it and they stung some shrooms . They only come around as the demand of food allows ... The pink sponges I have in the purple (also yellow and blue)version they are quite neat to get