you could try getting some of theat algae crubbing pad that you can cut mak it fit acrss the width of the inside of the return and pushit below the sirface of the water about 1 inch you do not want it to go all the way to the back of the skimmer otherwise it will rais the water level in the skimmer and will not skimm very well. I don't have a problem with my kids but it has been running for a few weeks now.

Bill