How to care for Non-Photosynthetic (NPS) corals in the aquarium?

Table of Contents

General information

Setting up a saltwater aquarium with non-photosynthetic (NPS) corals is a bigger challenge and requires a bit more commitment than maintaining photosynthetic corals. These corals don’t get food through photosynthesis from zooxanthellae, but from food that they actively capture from the water column.

While maintaining NPS corals may seem challenging, proper methods and filtration systems can greatly ease this process. Properly planning an aquarium for such corals involves several key principles.

Firstly, NPS corals require more frequent feeding, sometimes even several times a day. To meet this demand, it’s necessary to provide effective filtration and good water circulation. It’s worth designing a system that allows you to temporarily pause filtration during feeding to prevent removing food from the water before the corals have a chance to consume it.

The lighting in an NPS coral aquarium primarily serves an aesthetic purpose, enhancing the colors of the corals. It is not necessary for the corals’ nutrition, so it doesn’t need to be as intense as in the case of aquariums with photosynthetic corals.

Creating the right environment for NPS corals is a process that requires both knowledge and experience, but when managed properly, it can bring great satisfaction and become spectacularly beautiful.

Improved water filtration 

To meet the specific requirements associated with water filtration in a saltwater aquarium for NPS corals, it is necessary to use a more efficient filtration system. After feeding, the filtration system must quickly clean the water to remove food residues and other contaminants.

Mechanical Filtration: It is recommended to use an automatic mechanical filter that efficiently captures mechanical particles from the water. An example is the Smart roller by Reef Factory, where water flows through a special filtration material that traps contaminants. When the filtration material gets dirty, it automatically moves, extending the clean part and continuing the filtration process.

Protein Skimmer: The next step in water purification is using an oversized protein skimmer, which effectively removes proteins and other organic impurities from the water. It’s necessary to clean the skimmer cup every 2-3 days to maintain its effectiveness.

Frequent Water Changes: It’s also good practice to regularly replace a small volume of water – for example, 2% daily, ideally after feedings. This will help remove any pollutants after the corals’ meals and also balance the water parameters in the aquarium.

Biological Filtration: Using additional filtration media for biological filtration will help maintain proper water parameters. You can also use bacterial additives to increase the population of bacteria in the system, which in turn will more effectively remove organic pollutants. Examples include live rock in the sump, various plates, and biological balls.


At the time of writing this article, an automatic feeder for frozen foods has not yet appeared on the market, so this aspect cannot be automated yet. However, it is worth including regular feeding of frozen foods in the daily plan. From frozen foods, I recommend rotifers, artemia (baby brine shrimp), and Cyclop-eeze. The choice of food should be tailored to the needs of the specific coral – some require fine food, while others prefer larger pieces. Lack of experience in this field can be compensated for initially by mixing different types of food and observing the reaction of the corals. However, care should be taken to ensure that excess food does not settle to the bottom of the aquarium. If our circulation system is unable to cope with the remnants, it may be necessary to remove them by siphoning from the water.

Other foods

Other types of food include phytoplankton, amino acids, and dry foods. These alternatives should also be considered depending on the specific needs and type of corals being cultured.

Water circulation

Strong water circulation is crucial for two reasons. Firstly, it enables the even distribution of food to corals, facilitating their feeding and the removal of pollutants. Secondly, it helps maintain order in the aquarium by moving excess food to the sump, where it can be removed by mechanical filtration and other filtration systems. Strong circulation is therefore not only helpful but often essential for effectively maintaining the cleanliness and health of the aquarium ecosystem.


In this article, I have presented methods for adapting a saltwater aquarium to accommodate non-photosynthetic corals. Although the need for additional feeding may seem laborious, thoughtful design and preparation of the aquarium can greatly facilitate this process. Well-planned placement of filtration elements, strong water circulation, and regular feeding tailored to the needs of the corals are key aspects that will help maintain a healthy and beautiful aquarium with non-photosynthetic corals.

About the author

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Marek Protasewicz

Reefkeeping has been my passion for over 10 years now. I love learning. The hobby has taught me many valuable lessons, patience being the best example. Combining work and passion is my path. I run Crazy Coral, a marine aquarium shop, for a number of years. Building this business from the scratch I learnt from my own mistakes at a heavy cost.
Later I managed a project aimed at development of methods for quick growth of Corals in non-natural conditions. The project was carried out by Get Sales, Poland. Presently, I am responsible for distribution strategy at Reef Factory, of which I am a co-founder. The company produces smart devices for marine aquaristics. The last projects I have been involved in are Social Reef and ReefPedia.

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