Identification

[gmerek2]

What is this tiny brown stuff? Is it safe lol? It's only on one rock right now. Thanks!

[jimlin]

looks like colonial hydroids to me. i would try to remove it.

[gmerek2]

I think they are thank you. Will they sting me or do they just sting coral? This rock is getting scrubbed then boiled later!

[jimlin]

they didnt sting me when i was scrubbing them several years ago. i didnt boil, instead i just left the rock outside for about 6 months.

[Coral Hind]

I would just use kalk paste on them instead of removing the rock. Be careful boiling a rock as some corals contain toxins which the boiling turns into vapor and you can breath that in and cause some serious damage, some club members have even been sent to the hospital because of it. 

[sachabballi reef]

paging steveoutlaw....

[gmerek2]

What about the white stuff on the top of the rock? What is the maroon?

[gmerek2]

What about the white stuff on the top of the rock? What is the maroon?

[gmerek2]

Chose wrong picture. This is the right one.

[YHSublime]

Chose wrong picture. This is the right one.

 

I'm curious about that as well. I had some of this while I was cycling my tank, it went away.... 

[flooddc]

Some kind of sponge?

[gmerek2]

Looks spongy because it has a kind of fancy detail like frost on a window. Is the maroon on tip of the other rock normal?

[swimmatte]

Is the maroon stuff hard? If so, could it be coralline? If not, I'd guess cyano or red slime?

[jimlin]

looks like cyano or another type of bacteria to me. sponges in my experience that look like that usually hang out under the rock.

[gmerek2]

Well I learned today that coralline has many shades of red and also different colors. It's hard not slimy. You guys are good. The white feels like sponge. I bought/moved this 125 tank used 2 weeks ago that rock was moved and probably flipped over. The rocks have a variety of sponges. Will the light kill the sponge?

[LCDRDATA]

The rocks have a variety of sponges. Will the light kill the sponge?

 

Light won't kill the sponge directly, but does support the growth of algae that potentially can kill it. Exposure to air, on the other hand, is frequently fatal (if sometimes gradually so). Various fish and inverts may eat it as well.

[swimmatte]

Yep, coralline comes in TONS of colors. Once you get a solid coating throughout the tank it gives a nice look IMHO. Free coral! As for the sponge, like it was mentioned above, light won't hurt it, but air definitely will.