Soft corals are perfect for nano reef aquariums. They’re hardy, forgiving of minor mistakes, and full of motion and color. In a small tank where every inch matters, choosing the right soft corals can make the difference between a cluttered box of rock and a vibrant, thriving reef.

Why Soft Corals Shine in Nano Reefs

Soft corals lack a rigid skeleton, which makes them more tolerant of swings in parameters than many LPS and SPS species. That flexibility is ideal for tanks under 20 gallons, where chemistry can change quickly. They also tend to grow faster and accept a wider range of light and flow.

Before you stock your nano reef, be sure your basics are stable:

• Salinity: 1.024–1.026
• Temperature: 76–78°F (24–26°C)
• Alkalinity: 8–10 dKH
• Regular 10–20% weekly water changes

For more on keeping parameters steady in small tanks, see our guide on nano reef maintenance.

Best Beginner Soft Corals for Small Tanks

Mushroom Corals (Discosoma, Rhodactis, Ricordea)

Mushrooms are among the most forgiving corals you can keep. They tolerate lower light, moderate nutrients, and gentle to moderate flow. Place them on isolated rocks if you don’t want them to slowly spread across your aquascape.

• Lighting: Low to moderate
• Flow: Low to moderate, avoid direct blasts
• Tip: Start them on the sandbed and move up only if they stretch excessively.

Zoanthids & Palythoa

Zoanthids come in an incredible range of colors and patterns, making them ideal for adding visual impact in a tiny footprint. They form tight colonies that can cover rockwork and create bright islands of color.

• Lighting: Moderate
• Flow: Moderate, enough to keep detritus from settling
• Tip: Some species contain strong toxins; always handle with gloves and eye protection.

To design eye-catching layouts with zoanthids and mushrooms, check out our article on aquascaping a nano reef.

Green Star Polyps (GSP)

Green star polyps are a classic beginner coral, famous for their waving neon-green mat. In a nano tank, they can quickly overgrow rock, so plan ahead.

• Lighting: Low to high (very adaptable)
• Flow: Moderate to high to keep polyps clean
• Tip: Isolate GSP on a separate rock or back wall if you don’t want it spreading everywhere.

Leathers (Sarcophyton, Sinularia, Kenya Tree)

Leather corals add height and movement to a small system. Toadstools and Kenya trees sway beautifully and provide shelter for small fish and invertebrates.

• Lighting: Moderate
• Flow: Moderate to strong to help them shed their outer film
• Tip: They can release chemicals; run activated carbon and perform regular water changes.

Placement, Growth Control, and Long-Term Care

Space is your most precious resource in a nano reef. Plan coral placement with future growth in mind:

• Put fast-spreading corals (GSP, some mushrooms, Kenya tree) on isolated rocks.
• Reserve prime central spots for your favorite showpieces.
• Leave room between colonies so they don’t shade or sting each other.

Soft corals appreciate stable nutrients rather than ultra-sterile water. A lightly fed nano with a small clean-up crew often works best. For stocking ideas that pair well with soft corals, see our guide to nano reef fish.

Soft corals reward consistency more than perfection. Keep your routine simple, test regularly, and make small, gradual changes.

Soft corals are an excellent way to build a dynamic, colorful nano reef without demanding extreme equipment or experience. With thoughtful selection and placement, your small tank can become a thriving slice of the ocean that’s easy to enjoy and maintain for years.