quick question about coralline algae

[sharkboy]

It appears that there is coralline algae growing on my ls. Is this possible? At first I thought that it was some brown diatoms. As it developed and grew it is deffinitly purple in color.

 

[sharkboy]

no is not gooy or stringy. It seems to just sit on the sand. It seems more like a powder that can be disturbed quite easily when the sand is disturbed.

 

[bean 1]

I have the same situation going on in two of my tanks. I think mine is definitely coralline as it is purple and green. I have coralline exploding all over my tanks. The base rock that forms the base for my LR is now completely coralline covered. 3 sides of my tanks are coralline covered and I kind of like the way it looks as the tanks (100/75g) are built into the walls so you can only look into the tank from the front. I'm not so sure I like coralline on the sand and I probably need to increase my sand sifters to keep the sand turned over a little more frequently.
good luck...Bean