Hair algae on only one rock or one area in the tank?

[onlytoby]

So I have a small 20G tank with two large rocks to create a canyon. The rock on the left is perfect, not a single sign of algae. The rock on the right the entire top is covered in hair algae!

Does anybody know why this may be? Both rocks are the same height in the tank and should receive the same light as the Prime is in the middle of them.

 

[ZoWhat]

My first guess is both rocks has different compositions. One being more conducive to growing algae...maybe more porous

 

[onlytoby]

My first guess is both rocks has different compositions. One being more conducive to growing algae...maybe more porous

Ohh that's interesting I didn't think of that but I think you're right looking at it now. I will have to try to do my best to get rid of it and then make sure I turkey baster that rock a lot more frequently!