What is This? Its rapid growing?

[Neevitz]

I dont know what this is but within one month it has quadrupled in size. I am concerned it is not good for the tank. Please respond.

http://s669.photobucket.com/albums/vv55/Neevitz/?action=view&current=101_0125.jpg

 

[ccCapt]

I can't tell. Pic is too small and too blue. Take another pic without so much actinic lighting and don't make it so small.

 

[roka64]

I agree, that is a tough pic to determine what it is. Can you tell us more about it, is it red, blue, soft, hard...?