Is this algae good or bad? (Photo)

[Johny123]

My tank is about 4 months old. I am not a big fan of algae, unless it is considered beneficial to the tank.

See the greenish algae on the live rock right behind the Duncan. What is that?

Also...now that I have these corals, how much should I leave the lights on so they are well fed, without overdoing it as to cause algae growth? When the LED light is off, they all shrivel up during the day into nothing.

<a href="https://ibb.co/nNRoxQ"><img src="https://thumb.ibb.co/nNRoxQ/IMG_2104.jpg" alt="IMG_2104" border="0"></a>

[mcgyvr]

Its some type of green algae which is totally normal in a new tank .. picture is too far away to see any specific details.. keep maintaining low nitrates/phosphates and it shouldn't become an issue.. Do you have any snails to munch on it?

In general 6-8 hours of light is sufficient for corals..