ID alage
 

this is the first time i see this kinda alage in my tank they have been growing in the back of my cube tank and the power head
http://i1053.photobucket.com/albums/...g/P1040014.jpg

<a href="http://s1053.photobucket.com/albums/s464/alexafg/?action=view&amp;current=P1040014.jpg" target="_blank"><img src="http://i1053.photobucket.com/albums/s464/alexafg/P1040014.jpg" border="0" alt="Photobucket"></a>

Looks like some red and green cyano to me. Some could be coralline as well. The white sponges are generally harmless and disappear over time.

IMO only, I'm no expert.

Looks like red cyano and green hair algae to me. Hard to tell exactly from the pic though.