Green algae help

[rhorn67]

Can someone help me identify this type of green algae? It has began to cover the top of my live rock. It seems to only cover the parts of rock exposed to the lighting. Tank is in 6th week and finished initial cycle at week 4.

I do weekly water changes of 20-25%. Hydra 26 HD on for a total of 9 hours. 3hrs of ramp up 3hrs at full 3 hrs ramp down.

Params
salinity 1.025
PH 7.93-8.02
alk 10
calc 460
ammonia 0
nitrite 0
nitrate 5
phosphates 0
mag 1450

Thank you

 

[cloak]

Does it come off the rocks easily? If not, it's probably just a prelude to that purple coralline algae we all love so bad. GL.

 

[rhorn67]

I attempted to scrape it and it does not easily come off. Its not on any of my other surfaces such as the substrate, glass etc.