Within the reef aquarium hobby, you often hear the terms soft corals, LPS and SPS used to identify different groups of corals. Grouping corals in this fashion is useful because it not only describes the coral itself, but also helps aquarium hobbyists understand what a particular coral will need from us (lighting, placement, flow, parameters, etc.) in order to survive.
This is our third and final article in the series, if you missed the first two articles be sure to check out How to Care for LPS Corals and How to Care for SPS Corals when you’re done with this article. All of the articles are written in the same easy-to-understand, no nonsense style.
Before we dive into Soft coral care, let’s take a quick look at each coral type to identify their key features, similarities and differences:
Soft corals lack a rigid stony skeleton. Typically they require lower light and moderate to low water flow. They are often more forgiving with water quality and easier to care for. Common soft corals include Leathers, Zoanthids, Palythoa, Discosoma and Ricordia.
LPS: Large Polyp Stony Corals
Large Polyp Stony Corals consist of a rigid skeleton with large fleshy polyps. LPS usually require moderate to high light levels and moderate flow rates. They are a bit more forgiving with water quality compared to SPS corals. Growth rates and patterns vary dramatically from one species to another. Common LPS corals in the aquarium trade include Acanthastrea, Euphyllia, Favia, Fungia, Blastomussa, Dendrophyllia, and Tubastrea.
SPS: Small Polyp Stony Corals
Small Polyp Stony Corals have a rigid skeleton with small polyps and thin flesh surrounding the skeleton. They generally have high light requirements and prefer high water flow. SPS are very sensitive to water quality and are the most difficult corals to grow in an aquarium. Common SPS corals include Acropora, Montipora, Pocillopora, Stylophora, and Seriatopora.
Soft Corals are probably the most diverse group of corals as they come in a wide range of sizes, colors, and textures. With such a vast diversity comes a set of care guidelines that will vary widely depending on the exact type of soft corals you plan to keep.
The first and most important aspect to understand about soft corals is that they can be either photosynthetic or non-photosynthetic. Some soft corals are naturally found deeper in the ocean or in areas of low light such as underwater caves and crevices. These corals are generally non-photosynthetic and may be referred to as “NPS” corals. All of the energy these NPS corals use to grow will be directly from food such as zooplankton and these corals do not require high levels of light to thrive.
While “NPS” corals may be enticing as they do not need high levels of light, they are one of the most difficult corals to keep successfully, even rivaling the care of SPS corals. The reason is because they need to be fed frequently, 2-3 times per day or more, which can quickly fowl your aquarium water which will then lead to a quick demise. We only recommend these types of corals for very advanced hobbyists and they will do best in species specific aquariums that are dedicated to “NPS” corals only.
It is important to be knowledgeable about these “NPS” corals as you do not want to be fooled by your local fish store. It can be quite frustrating only to find out the beautiful Gorgonian or Sea Fan you just purchased will have a small chance of success in your home aquarium.
Now, lets talk about the easy ones, true photosynthetic soft corals. These corals are often considered good “beginner” corals as, generally speaking, they can be quite forgiving with water quality and light requirements. Soft Corals have a vast array of physical characteristics which, personally, I think captivates many new hobbyists.
When shopping for Soft Corals the same rules as LPS and SPS corals will apply, you want to look for healthy specimens. They should be open with polyps extended during the daytime. Avoid corals that might appear to be shriveled or have any kind of film/slime covering the coral. Being that soft corals lack a stony skeleton, a closed up soft coral can appear quite small but may expand exponentially depending on the type of coral. So, be sure you have plenty of room for the coral to open up when placed in your home aquarium.
You will want to be sure to acclimate your new soft coral, just like any other aquarium inhabitant. Drip acclimation is the best method to avoid stressing the coral. It may also be necessary to dip the coral but do your research first to ensure the chosen dip is suitable for the coral you are treating. Some coral dip methods are not suitable for soft corals.
Many soft corals have medium to low flow requirements. The same goes for lighting, medium to low light, and they can generally be placed in the lower region of your aquarium. One important factor to consider is that many soft corals are quite prolific and spread like wildfire in a healthy aquarium. This may be desirable to some but can quickly out-compete other corals in your aquarium. Therefore, sometimes it is best to isolate or place the coral in an area where it will not be of harm to other corals.
As far as feeding goes, this can be done minimally as the coral will get a majority of its energy from photosynthesis. If you do feed your corals, medium to small particle size foods are best. A good schedule for feeding soft corals is once or twice per week, in the evening, just after the lights have turned off.
Whether your a novice or seasoned hobbyist, understanding the different coral groups will help ensure your reef is successful. Not only will you save time and money, but also the many lives of unsuspecting coral. You will increase sustainability in the hobby and ensure the reef keeping hobby will be around for the generations of aquarists to come.