What effects does oils have on a skimmer?

Oils have hydrophobic effect to the bubble surface inhibiting the natural attractant hydrophilic bonds of salts, sugar, ammonia, most amino acids and most inorganic compounds. If concentrated levels of oils are present in the skimmer and/or water column you often will experience little to no foamate production, low air induction and inconsistent level settings within the skimmer. Often appearing as if the skimmer is running in fresh water with inconsistent bubble levels throughout, turbulent mixture of air and water within the upper body and opaque white appearance. New skimmers contain oils from manufacturing and handling and sometimes different product runs while have more oils present than others and it is suggested that a rinsing the skimmer in a solution of vinegar and water prior to setup. Then allow 3-4 weeks for the skimmer to fully break. Many fish and coral foods have oils as well as we introduce oils any time we stick our hands in the tank, add new plumbing, new equipment etc which could inhibit skimmer performance or delay break in time of a protein skimmer. Never adjust the output valve during this period.