A piture would be great. My old in sump skimmer used a small pump to introduce the water and 1 flow rate. I then adjusted the air to maintain a level. More air would lower the water level in the skimmer and keep it from overflowing. If you have this type, I had to check it everyday to keep the level right. With this type of skimmer, the water level in the sump may have something to do with it. With mine, the higher the sump water, the higher the water line would be in my skimmer. Thus I had to check it all the time because of the evaporation.

And with clear water comeing out, your just overflowing the skimmer.

My current skimmer has a valve on the pump and a tube for the air intake that has no adjustment. It will fill a gallon jug in 1 day if the pump is too high. But it's just water. Not skimmate. So I adjust the water flow to control the amount of skimming.