Bought a algae/coral rock....

I just bought a coral and only to find a lot of bad algae under it. I put it in my tank already and gather all my hermits to attack it. It's green and I can pull some of it off. They grow out like a spike in some places of the rock. How will the algae hurt my water?

Thanks!
GKW

 

Hmmm, can you post a picture? I have no idea...is it soft? calcareous? Just green spiky algae? Ill check it out.

 

I will try to post a pic later on today. It's green/yellowish. It's soft and I can pinch a chunk out. I just had a better look at it and it actually growing between the Anthelia's polyp too. How can I missed it!?

Thanks!
GKW

 

I found that those are the substances that grew with the coral, but I guess the tank was dirty and made it looks like algae.

I had brush most of it off before finding that out. It's thriving right now and has grew a few more stalks, but what are those substances?

Thanks!