Protein Skimmers are normally used in marine aquariums to remove dissolved organic waste.
Tiny air bubbles are passed through the protein skimmer and rise to the surface where they spill out into a collection chamber. On their journey through the water these bubbles attract dissolved proteins and other organic waste matter that cling to the bubbles surface. Once reaching the surface these bubbles spill over into the protein skimmers collecting chamber where they burst and leave a yellowish liquid of waste matter. The Protein skimmers collection chamber will need emptying from time to time depending on the speed of extraction of the proteins.
It is important to remove these proteins and organic matter because if they build up they will pollute and discolour the water.
There are two basic types of Protein Skimmers, those that operate using an air pump and those using a water pump with a venturi that creates the bubbles. The more sophisticated water pump venturi operated skimmers are more expensive but often have the benefit of external attachment from the aquarium.