Soft corals are the unsung heroes of captive corals because they are relatively easy to care for and exist in a range of brilliant colors, shapes, and sizes. They require minimal flow, prefer lower light conditions, are often affordable, are generally fast-growing, and in many cases are more forgiving and easier to care for than their LPS and SPS counterparts. With the right mix, you can design a breathtaking soft coral-dominated aquascape that rivals that of any mixed reef tank. 

What are Soft Corals?

As it pertains to the aquarium hobby, soft corals encompass any "coral" that does not excrete a rigid calcium carbonate-based skeletal structure. Leathers, Xenia, Sinularia, and Nepthea are all true soft corals that are primarily comprised of soft tissue and calcium-based sclerites that provide structure. The sclerites are like calcium slivers mixed into the soft tissue and can easily be seen when fragging a piece of soft coral.

We often also include Ricordia, Rhodactis, Zoanthids, Palythoa, Polyps, and even Gorgonians as soft corals, even though these technically belong to different scientific classifications and don't contain calcium sclerites. It helps to group these corals together in the hobby not only because of their physical characteristics but also because, for the most part, all of these "soft corals" have similar care requirements. 

It should be noted that we are specifically referring to photosynthetic soft corals in this video/article because non-photosynthetic soft corals (NPS) are drastically different and much more difficult in terms of care. NPS corals would include things like Chili Corals, Carnation corals, Dendros, some Gorgonians, and Sun corals.

WWC Solomon Hairy Leather
WWC Green Toadstool Leather
WWC Pulsing Xenia
WWC Neon Cabbage Leather
WWC Neon Clove Polyps
WWC Green Star Polyps

Photo Credit: World Wide Corals

Soft Coral Care Requirements

Soft corals are great for beginners because they are relatively easy to care for. They don't consume calcium and alkalinity like you would get with LPS and SPS corals so that means dosing is probably not required and they will prefer to have some level of nitrate and phosphate present in the water. The low light and low flow requirements mean you won't have to invest as much in your equipment too. 

While some hobbyists might turn their nose up at soft corals for being drab or bland, this couldn't be further from the truth. Soft corals exist in pretty much every color you can imagine from muted brown, pink, and beige to brilliant green, red, orange, and purple. The key to creating an inspiring soft coral tank is choosing a variety and placing them correctly in the tank so they can coexist.  

  • Flow: Low indirect water flow is ideal. You can usually get away with only using the return pump but if a powerhead is used, be sure it's not directly aimed at the soft corals. 
  • Lighting: 25 - 75 PAR  Yup, that is relatively low light levels meaning you don't need a high-output light. 
  • Diet: Soft corals appreciate regular feeding of small particle, plankton size foods. Spot feed 1- 3 per week based on the level of nutrients your tank can handle.
  • Placement: Most soft corals anchor onto the rocks directly and will be placed in the lower half of the tank. Isolating faster-growing soft corals on rock islands is common practice. 
  • Aggression: This varies depending on the exact type of coral. For the most part, they are fairly peaceful with one another but if they do irritate each other, it's generally not deadly as long as you move the offender. The most common issue is actually out-competing each other for real estate because the fast-growing softies like Xenia can take over an entire aquarium in just a few months.
  • Growth Rate: Medium to fast growth rates depending on the exact species. For example, Xenia and some button polyps are extremely fast-growing, so much so that we label them invasive. Leathers and Sinularia corals on the other hand are not anywhere near as invasive. 
  • Water Chemistry:
    • Water temperature 77° - 78°
    • Salinity 1.025 SG or 35 PPT
    • pH > 8.0
    • NO3 +/-5 ppm
    • PO4 0.05 - 0.1 ppm
    • Alkalinity 9 dKH
    • Calcium 400 - 425 ppm

Maintenance can be kept minimum with a weekly water change.  Soft coral tanks are the best for low maintenance because as long as you keep things stable with a regular water change, you won't have to worry about dosing. Just keep up with regular feeding and ensure nutrient levels are maintained within range. You can add trace elements and amino acids into the mix as the corals mature and spot-feed the corals to optimize their growth and coloration.  

Some soft corals are very fast-growing and can be considered a nuisance. If left to grow uncontrolled, they will take over the entire aquascape and outcompete slower-growing corals. Button Polyps, Green Star Polyps, Xenia, and Blue Anthelia are the worst offenders and should always be isolated. Even still, they can jump rocks and satellite colonies can pop up elsewhere; you want to be sure and remove these invasive corals from where they are not welcomed immediately. 

It's not uncommon for softy tanks to experience lush growth and creating frags to trade with friends is a great way to get new corals for your tank! In any case, you will likely need to move corals and trim them within the first year.  

Aquascape & Coral Placement 

Aquascape the aquarium minimally with plenty of room for growth and create isolated areas where you can keep certain types of soft corals separated from the main cluster of corals or rocks.  Leaving open sand space is ideal because you can anchor a brand new soft coral to a small piece of rubble and place that rubble on the sand to create an isolated colony.  Many soft corals grow fast but take note of those growth patterns when placing the corals.

Placement should be based on growth rates and patterns. While Xenia stays relatively short, they spread out and cover the aquascape in a hurry so isolate your Xenia far from other pieces of rock. Leathers and Sinularia tend to grow tall, like trees, so planting them towards the back where they won't be blocking shorter corals up front is good practice. Zoanthids and mushrooms both cover rocks and grouping them together by species is a pretty common practice.  A mushroom garden or zoanthid garden is the way to go and results in a grouping of brilliant colors.  

You should also think about the colors and get a variety of corals in the tank so you are not dominated by beige, brown, or light pink. Even if the corals have muted colors, the different shades and growth patterns together will create some uniqueness. 

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