Black spots on live rock???

[jad1217]

Recently (past month) i have notices some black hard spots growing on the coraline algae. It is hard, not soft or slimy. I have tried to scrub it off with a tooth brush with no results.

Anybody have a clue what it might be??

[smtank]

Need an image please.

[dartier]

It could just be black coraline. Coraline comes in all colours including black.

Dennis

[jad1217]

I'll get some pice when the lights come on

[MDO]

Originally Posted by jad1217

Recently (past month) i have notices some black hard spots growing on the coraline algae. It is hard, not soft or slimy. I have tried to scrub it off with a tooth brush with no results.

Anybody have a clue what it might be??

Is it fuzzy like or is it looks like its encrusting on the rock like coralline?

[TruReef]

black sponge? pics would help a lot...

[cloak]

Lobophora? This can appear black sometimes.

[jad1217]

Its hard black spots. hard like coraline algae. Not fuzzy or slick. Will get some pics up today.

[jad1217]

Here are some pics of the suspected problem

[Reverend Reefer]

Originally Posted by jad1217

Here are some pics of the suspected problem

OP: did you ever get a response about this? i just did a search and only a couple threads came up but no response really.

mine is the same as someone else mentioned, i found a lot of it when i lifted live rock from the sand and the part under the sand had black spots on it but i also have some growing on the top of a piece that is located on the top shelf...

both are hard and black. same live rock i've had for years. am i experiencing old tank syndrome??? i never did do what Paul B suggests regarding storm simulation and my reef has been looking a little drab recently, i'm probably at my 8 yrs or so...

[droog]

Hmm. I have this too on some of my LR, particularly that near the top of the tank. Its hard and encrusted similar to coralline (maybe it is black coralline algae?).

There were a few patches to start, but it does appear to be spreading. Would love to know if the OP or others were able to remove it.

-droog

[Reverend Reefer]

Originally Posted by droog

Hmm. I have this too on some of my LR, particularly that near the top of the tank. Its hard and encrusted similar to coralline (maybe it is black coralline algae?).

There were a few patches to start, but it does appear to be spreading. Would love to know if the OP or others were able to remove it.

-droog

personally, after reading a lot more about old tank syndrome, i was able to differentiate between 3 things. none of my photos ever look the way they do in the tank so unfortunately i have no photos but here goes:

the first black stuff i noticed turned out to be lobophora. sucks the big one. grows like crazy, super resilient, likes high and low flow, and seems to be tolerant of levels even in starving corals sort of conditions. hard to 'peel' off, feels like dried up leaves but harder. some people have a nice red variety, but mine was yellow brown in some lights, dark brown almost black in others. i think its a macro algae.

the second black stuff i noticed were signs of old tank syndrome. my rocks were buried in sand and after many years, basically went bad on the bottoms. the reason why they became visible was when i shifted some rocks around. i've since re-aquascaped my tank to limit the rock laying in the sand, committed to the artificial creations of storms once in a while based on what some old fart on RC said , and changed my old fine sand to larger particle aragonite. as well as some other stupid little things (bye bye DSB), all to avoid old tank syndrome in the future. by the way, this stuff stinks and is probably bad for you. i chipped most of it away and re-aquascaped using acrylic rods and hydraulic cement method (the work is worth the effort, trust me!).

the third black thing that looked most like what people often remark as looking like oil remains unknown. while some believe them to be black sponges, the type i had seemed so, non-porous, to me. i dunno. it was hard but sort of smooth and glossy looking, the way coraline is. who knows. i can tell you though, that after i introduced a black long spined urchin (originally to get rid of lobophora), it disappeared - presumably eaten by the urchin, which cleaned my live rock white! he eventually got too big and i had to trade him in.

anyways, i know that doesn't answer much but hope that helped.

by the way, the only thing that completely eradicated the lobophora was the long spined urchin combined with algaefix. the urchin ate most of it but it just kept popping back up in little spots here and there. the algaefix finished it off.