What is this?

[Chinese DNA]

Hi Everbody.
In my brother's tank, there are some black things being grown on the rock as attached photo. what is this?
The rock can be sun, and the tank is over one year. there are two marron, three ocellaris and four bule fish in my tank.
thanks




http://www.sonic2000.com/bbs/uploads/post-154-1137453603.jpg
http://www.sonic2000.com/bbs/uploads/post-154-1137453583.jpg
http://www.sonic2000.com/bbs/uploads/post-154-1137453612.jpg
http://www.sonic2000.com/bbs/uploads/post-154-1137453620.jpg
http://www.sonic2000.com/bbs/uploads/post-154-1137453628.jpg
http://www.sonic2000.com/bbs/uploads/post-154-1137453636.jpg







there is some green in the same rock. what is this?





http://www.sonic2000.com/bbs/uploads/post-154-1137453595.jpg

[Monkeyfish]

It all looks like algae to me.

[Chinese DNA]

Why my algae is black?

[TippyToeX]

Mayeb it's a sponge? It's too tough to say from the pics. Also, it this balck stuff easy to remove? Cyanobacteriacan be black too.

[Chinese DNA]

Can I keep reef with sun?
If this black is made by sun, I think I can't keep reef.

[TippyToeX]

Sunlight is the best light to have. Many people would dream of being able to have their tank near a window or below a sky light to make use of the sunlight. :)

Nutrients cause algae. If this is getting out of hand I would imagine that is the source of your problems, nutrients.

[Chinese DNA]

Thank you very much.
I just don't know why other people's rock grow brown algae or green algae,but my brother's grow black algae? oh!! this rock is dead, not live rock. whether dead rock can grow black algae out or not?
thanks