Dark algae on Chaeto

[chef_pinky]

So I have this dark algae growing on top of my chaeto:

Any suggestions on how I can resolve this issue? This is the light I am currently using in my sump:
https://www.ebay.com/p/Innovative-M...1%26rvr_ts%3Ddb26cb0f1650ac3db5a24237ffff8fe6

 

[cracker]

Sorry Friend, under those lights ,it's very hard to tell .