does green hair algae spread?

[Egg]

I added some coral on rock to my tank today. I just noticed the rock has green hair algae. Will it spread? Should I remove the rock?

 

[chefjpaul]

Invest in some plutonium, that should wipe it out.

Or
Take it out and scrub it off if it bothers you. Yes it can spread depending upon your maintenance and nutrients.

 

[Egg]

I scrubbed it off but there is still some left. I think I might get an emerald crab, C hair, tang ,or rabbitfish.

 

[Reefing Madness]

It will only spread if your tanks nutrient level allows it to.

 

[Kungpaoshizi]

It will spread over time, np.
During a water change just take it out, put it in a bucket with old water, scrub it off, rinse it pretty well, plop it back in. Algae can slow it's metabolism if there's no food present. It will hold out a long time before it dies.