All protein skimmer operate using similar basic operation in which water will be directed through a chamber and then come into contact with high volumes of fine bubbles for maximum air/water surface contact. The bubbles, which are lighter and heavily charged will attract protein binding and then float to the surface. Currently there are two different systems, one is using the co-current flow and another is the counter-current system. A Venturi Protein Skimmer is a good example that works based on the co-current flow while Beckett Protein Skimmer is another that type that employs the counter current flow system.
Other than ensuring better water quality, buying a protein skimmer can actually save lot of money in the long run. Basically a cubic meter of water for saltwater aquarium can cost quite a lot and it’s much cheaper to treat the water than using fresh water and then increase the usage of marine salt. If you are a serious pet fish hobbyist, I would suggest getting a unit even though the price can be quite high, it is actually a worthy investment.
FAQ: Is it necessary to have protein skimmer in freshwater tank?
Related fish topic: aquarium pH testing using special kit