Have no idea. The biggest issue it grows on dead portion of corals as well and frag rack. nothing on rocks. Clean - no algae at all on rocks.

Would help if you could get a close up of the organism itself...

Do you have access to a microscope? You wouldn't need a very high powered one to tell you what family you're dealing with. The course of treatment is highly dependent on a positive ID. Could be dinos, could be a cyanobacteria, could be some other random form of algae.

Unfortunately don't have any :) Will try to get better picture in weekend. I have reduce the lighting period and will try to feed less.

It's look like sponges to me are they are white in colour ?

no it is brown-grey - ish color. They I very slim, I cannot pull it with my fingers just brushing.

So finally managed to take a decent picture. And it starts to grow on rocks as well. Anyone can chime?

http://farm6.staticflickr.com/5451/9...92ef6cbe_b.jpg


In corner of my Acan there is a dead spot. It is growing fast!
http://farm6.staticflickr.com/5503/9...dbb3074a_b.jpg

Weird...

I'm no expert, but that almost looks like a bacterial fungus to me...

Would be an odd colour for an algae...???

what is the treatment for bacteria fungus?