What's this on Micro?

[Captain45]

What's this growing on my micromussa skeleton? It's a puffy, greyish, soft, slimy semi translucent substance.

Heres a pic with flash on and off.

 

[ISpeakForTheSeas]

What's this growing on my micromussa skeleton? It's a puffy, greyish, soft, slimy semi translucent substance.

Heres a pic with flash on and off.

That's a sponge - as long as it doesn't start growing over and smothering the coral itself, it's a harmless filter feeder. Where it's growing now (around the base of the coral, rather than on the coral itself) isn't an issue, but you would want to keep an eye on it just because of how close it is to the coral. It most likely won't be an issue though.

 

[Captain45]

That's a sponge - as long as it doesn't start growing over and smothering the coral itself, it's a harmless filter feeder. Where it's growing now (around the base of the coral, rather than on the coral itself) isn't an issue, but you would want to keep an eye on it just because of how close it is to the coral. It most likely won't be an issue though.

Thanks. I think I'd prefer it off before it grows anymore, what's the best and safest way to remove these? Light toothbrushing in a separate bowl?

 

[JPM San Diego]

Best of luck. I have tried various options to remove sponge including straight H2O2.
(Thank the Lord I didn't lose the favia) Nothing ever worked.
Eventually I learned to live with it and embrace a little extra diversity in my tank, even if it is a dull grey.
The favia eventually grew over it so it is not very noticeable now.

 

[olonmv]

Thanks. I think I'd prefer it off before it grows anymore, what's the best and safest way to remove these? Light toothbrushing in a separate bowl?

Exposure to air usually kills sponges.

 

[vetteguy53081]

Thanks. I think I'd prefer it off before it grows anymore, what's the best and safest way to remove these? Light toothbrushing in a separate bowl?

Good call. Its clatharina sponge which will overtake coral in time.
How to remove: Use a dental pick or small crochet needle and pull off - Best done in container of tank water to reduce any chance of toxins which should be low with this sponge.
Inject vinegar via syringe which will shrink it

 

[ISpeakForTheSeas]

Thanks. I think I'd prefer it off before it grows anymore, what's the best and safest way to remove these? Light toothbrushing in a separate bowl?

Probably the best suggestion for a situation like this would be to scrape it off and suction it out (I’ve heard suggestions to do both at once with a steel straw; that’s probably a good idea).

Edit: the separate bowl of tank water to clean it in may be a good idea as well.