Yes. Protein skimmers remove nutrients from the aquarium water.

A protein skimmer increases the efficiency of large aquarium filtration systems.
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Aquarium protein skimmers are one of the most important devices you can use to maintain water quality in a . Protein skimming removes organic pollutants before they break down into nitrates and phosphates. The improved water quality is beneficial to fish and corals and may reduce the frequency in which water changes are necessary.
Aquarium Protein Skimmer by Dreadnaught426 is licensed under the  license.
Photo provided by Flickr
The Cyclone Bak-Pak incorporates a biological filter along with a very nice protein skimmer in one unit, which hangs on the back of your aquarium. No extra plumbing is required, in fact all you need to do is level unit with the adjustment screws provided in the unit. If you have ammonia in your aquarium water it cannot be removed by protein skimming.
Photo provided by FlickrProtein skimmers physically remove the nitrogen-rich, foamy organics from the aquarium.
Photo provided by FlickrProtein skimmer with aquarium pump for saltwater aquariums up to 100 gallons.
Photo provided by Flickr
I have run many marine fish only and reef aquariums with and without protein skimmers for many years. To this day I can not say that there is a noticeable benefit running a protein skimmer. I ran a protein skimmer for many years on a fish only system and then I took it off the system. The system was ran for years without a protein skimmer and there was no noticeable affect on fish health. I have also set up many reef systems without protein skimmers, and had excellent results with small polypstony (SPS) corals growing very well, and several species of marine fish spawning. Some reef system setups had undetectable nitrate levels after being set up for years.The theory behind running a protein skimmer on a marine aquarium sounds good, but in reality its impact on well established marine aquarium appears to be minimal. Real independent research needs to be done to validate the value of running a protein skimmer on a marine system. With all the examples of marine aquariums that are doing exceptionally well without protein skimmers, I am finding it harder and harder to justify the expense for all marine aquariums.If you have a saltwater aquarium, you would definitely benefit from a protein skimmer because of fewer water changes, nitrate levels remain low, and the skimmer will oxygenate the water to a very high level, which is useful for the beneficial bacteria (that use oxygen) that break down ammonia and nitrite into nitrate.When the amount of water is small, such as in a Nano tank, it gets polluted easily and that could be a problem. The Nano protein skimmer for Nano saltwater aquariums can help to correct this issue.There are some saltwater aquarium hobbyists that don’t use protein skimmers and their tanks do just fine, but using a protein skimmer really helps with easier maintenance of the tank.Actually, even if your protein skimmer is designed for a larger saltwater aquarium, it’s not possible for the protein skimmer to achieve a really low organic nutrient level in which the corals wouldn’t have enough food. Your saltwater aquarium will never be as clean as the ocean water, so you shouldn’t worry about the lack of nutrients for your corals.