Coraline Algae?

[ZJGMoparman]

So I've had my 20 gallon nano up and going for 6 months now. The tank is doing great; fish look healthy and are growing, corals are opening nice (some showing more growth than others). I've finally started to see some coraline algae growth on the rocks and powerheads. I've also noticed some white crusty stuff growing on the back glass. This stuff is more of a white color. Is this a type of coraline algae as well? Or what is it?

 

[Red_Beard]

Those look like spirorbid worms, good sign stuff is going right!