Brown algae

[roberts01]

Getting this strange algae on sand, and on one rock, looks like gha but brown, no bubbles so not dinos, after cleaning sand appears in 2 days.

Tankrunning 4months 630l running fm zeolight
Running t5
Huge skimmer
Plenty of flow
Po4 and nitrates 0

Had the sump covered with it aswell but cleaned it. Cuc does not help. Maybe its the ugly phase?

What is it and how could i fight it?

Any help would be appreciated

 

[Jose Mayo]

You have there a beginning of infestation of Neomeris annulata, which should withdraw ...

The other algae, it may be the "ugly phase", can wait.

Best regards