green algae on live rock

[mrcopitr]

Hi Guys,

My new reef has been up and running for 5 weeks now....the rock are cured and my snails and crabs are doing fine and the red lip blenny is taking care of filamentuous algae that are growing on the glass....but since a few days I have been noticing green algae growing on my rock..particularly on the rock which tend to be white in color...this green algae resemble coraline algae...it is something I could not crape off or removed by hand like you can usually do with other type of filament algae. I'm using r/o di water, the skimmer is going strong and I've been doing regularly (twice a week...30 gal water cahnges)..my tank is a 86 gal....

I'm running power compact for about 8 hours a day....

Is this green algae a normal occuring in a new reef tank...

Thank you all

Marco