Help ID gray growth

[Boaz]

Need some help with IDFor this growth in my tank. Looks blue under blue lights. I’d call it slime to the touch. I first saw it in a shaded area in a rock cave. Thanks in advance.

 

[KrisReef]

Appears to be a sponge. Very good for diversity

 

[vetteguy53081]

Need some help with IDFor this growth in my tank. Looks blue under blue lights. I’d call it slime to the touch. I first saw it in a shaded area in a rock cave. Thanks in advance.

Either sponge ot chrysophytes but sponge favor dark, low flow areas so it is poriferan sponge and likely clatharina. It will further spread and you want to pull gently with dental pick or small crochet needle and remove and discard

 

[Boaz]

Thank you. I haven’t tried to remove it yet. Will have to pull the rock and see what I can do.

 

[JPM San Diego]

Looks very much like a sponge to me. The amorphous shape and pores on the surface are characteristic.
I would not be in a rush to remove it. How fast is it growing? Are you concerned it will over grow your rockwork?
I have several slow growing sponges that add a bit of diversity and color to my aquarium.
I have no intention of removing them.
The fact that it is blue is a plus. I recently added a blue sponge to my tank intentionally.

 

[Just John]

Thank you. I haven’t tried to remove it yet. Will have to pull the rock and see what I can do.

A lot of sponges can be killed simply by removing them from water and letting some air get in them, but I don't know if it would apply to this one. @vetteguy53081do you know about this one?

 

[vetteguy53081]

A lot of sponges can be killed simply by removing them from water and letting some air get in them, but I don't know if it would apply to this one. @vetteguy53081do you know about this one?

No air on this one, However injected with vinegar but I mentioned removal above

 

[ISpeakForTheSeas]

Personally, I’d keep the sponge - they’re usually harmless filter feeders (the only times I’ve seen them cause problems is if they’re an invasive kind that starts growing over and smothering corals).

 

[Boaz]

It started in a cave and one spot for several weeks. Yesterday, while cleaning I moved a rock and found two more. So far it’s only been under rock and seemed to stay way from light. I thought it was a sponge, but only had the one. Now that I see it spreading, thought it might be something to look into. I’ll be interested to see what it does in the light, since I uncovered it. has not been near any coral so far. I’ll try to get a few more pictures. Quite a vibrate blue under my lights, but hard to get a good photo. Appreciate all the comments.

 

[Boaz]

Here’s a few more photo’s for anyone researching similar.