What are these?

Not sure what these are. They've started growing out of my Live Rock before. Are they good? Bad? What should I do with them?

 

spindleweed I think

 

Neomeris annulata...calcium based algae...not terribly common, but sometimes comes in as a hitchhiker...some say it will grow out of control, although I've never had that issue myself.

 

It's actually a neat little macroalgae that is difficult to keep. Normally, it dies off on it's own. However, there was someone in my reef club that had it out of control. (Don't worry about these pics. I've only seen this happen once and I've been in this hobby many years).

 

I kinda like it actually.;D8)

 

So is it a sign of good or bad water conditions? Someone said it's Calcium based. Should those levels be given more attention?
Thanks again everybody!

 

If you had a bunch of reef-building corals, and you had a whole bunch of this algae, then certainly. It's going to be competing with them for Calcium, Magnesium, Strontium, and Alkalinity. However, with the small amount you have, I wouldn't really worry about it much beyond your normal testing/supplementation routine.

 

Gotcha. Thanks everyone!