If you decided to pass on the Bubble Magus Curve Protein Skimmer because your water level fluctuates, then an ASM G-2 Series is the protein skimmer for you. This skimmer will maintain a constant bubble level as your water level fluctuates. This is great if you do not have an automatic top off system.
The ASM G-2 Series produces more noise than most skimmers and you are more likely to hear the operation of the pump. These protein skimmers also lack a diffuser plate, and are less efficient than most cone type skimmers. This being said, they are still the obvious choice for those who cannot maintain a constant water level in their skimmer space.
In simple terms a Protein Skimmer is a container filled with a combination of air and water that allows for the filtration and collection of excess food, waste, and debris which would otherwise pollute your tank.
In addition to filtering out waste, a protein skimmer is a great way to promote gas exchange within your aquarium. As your fish consume available oxygen, producing carbon dioxide, we need to replace the oxygen and remove the carbon dioxide. Protein skimmers do this by supplying fresh oxygen to the tank in the form of bubbles and also create surface movement to allow for carbon dioxide to escape.