Green stuff on the water surface !:(

[megs_clark]

Im not familier with the unit. But any water pouring back into the tank is breaking the water surface, and water being skimmed off the surface of the water is also, but it need to be a big enough space. I dont know how the system works on the redsea but with the skimmer being down perhaps thats why? Was water being sucked into the skimmer pouring back into the main water when the skimmer was working and isnt now?