Hard Brown Algae that forms on tank

[mrg02d]

Hello all,
My tank has been up and running for about 9 months now. For some time, I have been having this hard brown algae that forms all over the sides of the tank. It is flat like coralline algae and quite a pain to remove. I have to use a sharp piece of plastic to "shave" the stuff off. It forms in a few days time and then this hairy stuff forms on top of it. I see my snails munching on it all the time.

Aside from that, there is no other algae in the tank. My cyanobacteria problem just went away despite me getting lazy with water changes/filter cleanings.

I just dont know what this is. Its hard like coralline, but looks different and grows FAST! It also seems to be what is sustaining all my snails since they have nothing else to eat. (The live rocks just have coralline on them).

My tank is a 20gallon with 20lbs of live rock and alot of corals. I have two clownfish, one sixline wrasse, a crocea clam, a skunk cleaner shrimp, and a handful of hermits.

I have a good bit of flow, but nothing crazy. I also have 96W of T5 lighting.

Thanks!
Matt

 

[shabubbles]

We're starting to have hard brown stuff growing in our tank too! It's on the corners and does not come off when I use the magnet glass cleaner. We had our run of diatoms that is almost gone. Ours are just tiny dots but I don't want them getting any larger. We are starting to grow purple, red and green coralline on our LR but non on the glass so far. Aren't diatoms supposed to be easy to wipe of tank surfaces?

 

[bribo12]

Look up lobophora and see if that is it, it's a hard encrusting/plating algae