[pogodzib]

That often happens with new skimmers or skimmers that aren't placed in a section of the sump that has baffles. There are boxes that are made of the skimmer outlet pipe to dump into that helps to reduce getting microbubbles into tanks. I'd start off by turning the air intake into the skimmer down some to see if it help while still producing skimmate, followed by giving it a couple days to see if it reduces on its own, followed by adjusting the skimmer outlet by adding a box or foam pad below the outlet pipe to reduce the microbubbles.