HELP
 

Hello everybody i get a piece of rLR 2 days ago but the LR has attached this little green-brown plant .
I dont know if this is a pest or is a macroalge if somebody outhere can help me to identify this plant will b amazing
Thanks to all of you

Looks like macro to me

I would let it grow, looks like macro algae to me. Not always easy to identify, apparently there are nearly 10K types of marine algae out there (http://www.seaweed.ie/index.php). If you are really worried, you could treat it with hydrogen peroxide to kill of the algae, but personally I would just let it grow for now and see how it looks and if anything will eat it (fish cleaner crew).