What is this growing in our reef tank?

I have a 100 gallon salt water tank..We bought this love live rock several months ago...with mushrooms, corals and sponges already established...and this yellow, tan area that started out small has been spreading over much of the rock and is very invasive to the corals around it. Not sure what it is, whether I should try and treat it, or remove the whole rock altogether to keep it from spreading.

 

It looks like some kind of sponge. Have you tried to manually remove it? I've removed sponges and they come off pretty easily.

How bit is it now?

I'd wait for a more experienced opinion, but my thought is to remove the rock to some tank water, pull as much off as you can, rinse in some clean tank water (to remove any bits that might spread) and return to tank.

Rick

 

No I have never tried to remove it...was unable to upload a better picture of it...but it covers about a 6inch by 6 inch patch...and appears to be mowing over corals in its path...

 

It looks to be a sponge to me also. Definitely remove it if you like the corals it is approaching and mowing over.

 

Hmmm...sounds like i should have asked someone sooner...ready to give it a try now....this may be a dumb question but can i just peel it off with my bare hands?

 

You should be able to. Might be safer to wear nitrile gloves for you. Be prepared for it to grow back as it is hard to remove all of the sponge. Pulling the rock out of the water should be they way you want to do it so you do not spread it through the rest of your tank. Rinse of the rock well with saltwater after removing the sponge before putting it back in your tank.

 

okay...well that was unexpectedly gross and time consuming....but seemed marginally successful....there was no peeling involved....lots of black and yellow sponge ooze all over and in the nooks and crannies of the rock....scraped off with a butter knife what i could...scrubbed with a toothbrush in the nooks...it had already invaded the corals...ooze under the attached structure...I took some of the coral that was covered off....I guess it remains to be seen if it survives...there are still many nooks with black in them...not sure if this will just grow into a new sponge, or die.

 

Might die since you had it out of the water and went after it so aggressively. Sponges generally do not do well when exposed to air for extended periods.

 

Thanks for your help....