Soft Coral Care Guide: Leathers, Xenia & Kenya Tree

1. What Are Soft Corals?

Soft corals belong to the order Alcyonacea within the class Anthozoa [1]. Unlike stony corals (LPS and SPS), they don’t build a hard calcium carbonate skeleton [2]. Instead, their bodies are supported by tiny sclerites — microscopic spike-like calcium structures embedded in soft tissue — combined with internal water pressure that gives them shape [1].

For reef tanks, this means soft corals don’t consume calcium and alkalinity the way stony corals do [3]. A tank dominated by softies can run with minimal dosing [4]. They are widely considered the easiest reef tank to maintain and the natural starting point for new reefers alongside mushrooms and zoanthids. [5]

The soft-coral group in the aquarium hobby is dominated by a handful of genera, each with distinct shapes, colors, and behaviors [6]. Most are tolerant of imperfect conditions, hardy across parameter swings, and reproduce vigorously in established tanks [7]. The trade-off: many produce allelopathic chemicals — toxins that suppress nearby stony corals — making mixed-tank planning essential [8]. [1]

2. The Major Soft Coral Genera

Six genera dominate the soft coral aquarium trade [9]. Identification matters because care, growth speed, and allelopathy aggression vary significantly. [10]

Several other genera appear less commonly: Lobophytum (encrusting leather), Briareum (star polyps), Pachyclavularia (green star polyps), and Anthelia (waving hand) [11]. Care patterns are similar to the major six. [12]

3. Sarcophyton (Toadstool Leather)

Sarcophyton — commonly called “toadstool leather” or simply “leathers” — produces the iconic mushroom-cap shape that defines soft coral aesthetics for many reefers [3]. Mature specimens can exceed 30 cm across. [13]

Identification

• Single stalk with a flat or undulating cap (the “mushroom” shape) [14]
• Polyps fully extended cover the cap surface like a fuzzy layer [1]
• Colors typically tan, yellow, green, or cream; some neon-green Sarcophyton morphs trade as designer specimens [2]
• Common species: S. ehrenbergi, S. glaucum, S. elegans [3]

The Shedding Cycle

Sarcophyton periodically shed a wax-like surface layer [4]. The polyps retract entirely and the cap appears slimy or pale for 1–3 days [5]. This is normal behavior — the leather is sloughing off dead surface tissue and pests — not a sign of disease [6]. After shedding, the colony emerges with fresh-looking polyp extension [7]. Healthy specimens shed every 4–8 weeks. [8]

Designer Morphs

• Neon Green Sarcophyton — brilliant fluorescent green; one of the most photogenic soft corals. [9]
• Yellow Cabbage Leather — bright yellow undulating cap. [10]
• Long Polyp Sarcophyton — specific lineages with longer-than-typical polyp extension. [11]

4. Sinularia (Finger Leather)

Sinularia grows as branching, finger-like extensions rather than the cap shape of Sarcophyton [12]. The genus includes the “cabbage leather,” “flexible leather,” and various branching morphs [4].

Identification

• Branched body with finger-like or lobed extensions reaching upward [13]
• Polyps cover the surface; when fully extended, the entire branch appears fuzzy [14]
• Tan to brown most common; some species produce striking green or purple morphs [1]
• Common species: S. flexibilis, S. dura, S. mollis [2]

Notable Behavior

Sinularia produces the strongest allelopathic compounds of any common soft coral genus — toxins specifically targeting Acropora and other stony corals [3]. A large Sinularia colony in a mixed-SPS tank can chronically suppress nearby Acropora growth even with adequate water changes [5]. Plan SPS placement carefully around Sinularia, or designate one tank zone for each [4]. [2]

5. Xenia (Pulsing Xenia)

Xenia is the only soft coral with a visible autonomous pulsing motion [5]. The polyps open and close their feathered tentacles in a rhythmic clapping pattern that resembles tiny hands waving [6].

Identification

• Slender stalks with feathered, multi-fingered polyps at the top [6]
• Polyps clap rhythmically at about 30–60 cycles per minute when healthy [7]
• Cream, white, or pale pink coloration most common [8]
• Common species: X. elongata, X. umbellata

The Boom-Bust Cycle

Xenia is notorious for unpredictable boom-bust population cycles [9]. A healthy colony reproduces rapidly — doubling its mass every 2–4 weeks in some tanks — until something triggers a collapse [10]. The entire population can melt within days, only to slowly recover months later [6]. Causes are not fully understood; theories include trace element depletion, allelopathic competition, and tank chemistry shifts [11]. [1]

6. Kenya Tree (Capnella)

Capnella imbricata — the Kenya tree — is one of the most affordable and fastest-growing soft corals in the hobby [7]. Identifiable by its tree-like branching structure and small tightly-packed polyps. [12]

Identification

• Tree or bush-shaped branching with secondary and tertiary sub-branches [13]
• Small polyps cover all branch surfaces densely
• Brown to tan most common; occasional pink and purple lineages [14]
• Mature colonies reach 30–50 cm tall

Drop-and-Grow Propagation

Kenya tree multiplies by dropping branchlets from its main body [1]. The dropped pieces roll along the substrate, eventually settling against rockwork where they encrust and develop into new colonies [2]. This means a single Kenya tree can colonize an entire tank zone within 6–12 months without intentional fragging [3]. Useful for fast tank establishment, problematic for tight mixed gardens. [4]

7. Cladiella (Colt Coral)

Cladiella — commonly called colt coral, antler coral, or stubby leather — produces stout, lobed branching shapes resembling small antlers [8].

Identification

• Stubby branching with thick lobed tips
• Polyps small and densely packed
• Tan to cream coloration most common
• Mature colonies reach 15–30 cm wide

Cladiella is one of the most beginner-friendly soft corals: easy growth, modest allelopathy, slow enough that it doesn’t overrun a tank, and tolerates wider parameter swings than most [5]. A common first coral for new reefers transitioning beyond mushrooms and zoanthids. [6]

8. Tank Requirements

Soft corals are the most parameter-flexible reef corals [7]. They tolerate wider parameter ranges than any other group and rarely fail due to chemistry alone [2].

Soft corals thrive at the nutrient levels considered too high for SPS [8]. In an SPS-tuned ULN tank, soft corals often pale, slow growth, and become less photogenic [9]. Many reefers report ideal soft-coral coloration at nitrate 10–15 ppm and phosphate 0.10–0.15 ppm [10]. See the reef chemistry guide for parameter management [11]. [5]

9. Lighting & Flow

Lighting

Soft corals are flexible — they tolerate PAR from 30 to 200+ with adjustments to coloration [9].

• Sarcophyton, Sinularia, Cladiella, Capnella: 50–150 PAR [12]. Higher PAR drives growth but can pale tan and brown morphs. [13]
• Xenia: 30–120 PAR. Very flexible. Pulsing behavior is most pronounced at PAR 60–100. [14]
• Lemnalia: 50–120 PAR. Prefers slightly lower light than the other genera. [1]

Flow

Soft corals prefer moderate, turbulent flow with periodic stronger pulses to deliver food and clear debris from the polyp surfaces. [2]

• Direct laminar flow folds and damages the soft tissue [3]. Indirect or random pulse modes work best. [4]
• Xenia pulses more vigorously in stronger flow — pulsing behavior is partially flow-driven. [5]
• Sarcophyton in too-strong flow rarely opens its polyps fully [6]. Move to a calmer zone if polyps stay retracted. [7]

See the water flow guide for tank-wide flow strategy. [8]

10. Feeding

Soft corals are primarily photosynthetic and absorption feeders [9]. They derive most of their energy from zooxanthellae and from absorbing dissolved organics through their tissue [10]. [2]

• Active target feeding is unnecessary. Soft coral polyps are too small to capture meaty meals like mysis. [11]
• Dissolved nutrients drive growth. Tank feeding fish, dosing phytoplankton, or simply letting fish waste accumulate at modest levels supports vigorous soft-coral growth. [12]
• Reef Roids or fine particulate 1–2 times per week can enhance growth in low-bioload tanks. [13]
• Iodine supplementation historically claimed to benefit soft corals; modern reefing largely considers this unnecessary if water changes are regular. [14]

11. Allelopathy & Chemical Warfare

Allelopathic intensity varies by genus [5]: [1]

• Sinularia: highest. Strong suppression of Acropora and other SPS even at modest colony sizes. [1]
• Sarcophyton: high. Can suppress SPS growth in mixed tanks.
• Cladiella, Capnella, Lemnalia: moderate. Mostly affects directly adjacent stony corals. [2]
• Xenia: moderate. Allelopathy combined with rapid spread makes Xenia particularly problematic in mixed tanks. [3]

Mitigation Strategies

• Activated carbon — weekly carbon refresh significantly reduces dissolved allelopathic toxins. [4]
• Larger water changes — 15–20% weekly removes accumulated toxins. [5]
• Physical separation — designate one tank zone for softies, another for stony corals. [6]
• Dedicated soft-coral garden tank — the most reliable approach is to keep softies in their own display. [7]
• Strong protein skimming — removes some dissolved organic toxins along with proteins. [8]

For pure soft-coral “garden reef” tanks (no stony corals), allelopathy is a non-issue — all the residents are equally tolerant. [9]

12. Fragging Soft Corals

Soft corals are among the easiest corals to frag in the hobby — nearly as easy as mushroom corals [10]. See the complete fragging guide for tools and dipping context. [11]

Sarcophyton / Sinularia / Cladiella

Xenia / Capnella

Even easier — both genera multiply by themselves [6]. Xenia drops baby polyps that attach to nearby surfaces [7]. Kenya tree (Capnella) drops branchlets that roll, attach, and grow [8]. For intentional fragging, simply cut a small piece and place against rubble; it attaches within 5–7 days. [9]

13. Common Problems

Polyps Not Opening

Cause: too much flow, too much light, recent stress, or shedding cycle (Sarcophyton) [10]. For shedding, wait 1–3 days for the cycle to complete [11]. For flow/light issues, move to a calmer or shaded zone. [12]

Soft Coral Melting

Sudden tissue dissolution — the coral “melts” into mucous within hours [13]. Most common in Xenia (the boom-bust melt) but can affect any soft coral [14]. Causes: severe parameter swing, ammonia spike, allelopathic attack from a neighbor [1]. Action: remove the melting colony to prevent ammonia spike, perform large water change, test parameters [2]. [3]

Bleaching

Soft corals can bleach under sudden lighting changes or temperature swings [3]. Symptoms: pale or white coloration with retained shape [4]. Treatment: reduce light or stabilize temperature, increase feeding (dissolved organics), wait 4–8 weeks [5]. Most soft corals recover. [4]

Overgrowth in Mixed Tanks

Xenia, Kenya tree, and to a lesser extent Sinularia can overgrow rockwork within months [6]. Active management is required: prune regularly with scissors, remove and trade excess frags, or designate a soft-coral-only tank zone. [7]

Brown Polyps from High Nutrients

In very high-nutrient tanks (NO3 above 30, PO4 above 0.20), soft corals can darken to brown as zooxanthellae proliferate [8]. Cosmetic issue, not a health issue. Modestly reducing nutrients with skimmer adjustment restores brighter color over 4–6 weeks [9]. [2]

14. Where to Buy

AllCorals tracks soft coral listings from 14+ Thai reef shops [10]. Browse current inventory:

• All soft coral listings
• Sarcophyton (toadstool leather)
• Sinularia (finger leather)
• Xenia (pulsing)
• Kenya tree (Capnella)
• Colt coral (Cladiella)

For broader beginner-coral context, see the beginner corals guide, mushroom corals guide, and zoanthids guide [11]. The shops directory lists every tracked Thai reef shop. [12]

15. Frequently Asked Questions

References

1. Corals of the World — Order Alcyonacea overview [1]
2. Reef Builders — Soft Coral Garden Reef Setup [2]
3. Tidal Gardens — Sarcophyton Toadstool Care Guide
4. Tidal Gardens — Sinularia Finger Leather Care
5. Advanced Aquarist — Soft Coral Allelopathy Research
6. Reefs.com — Xenia Care & Pulsing Behavior
7. Saltwater Aquarium Blog — Kenya Tree (Capnella) Care [3]
8. Reef Chasers — Cladiella Colt Coral Care
9. Bulk Reef Supply — Soft Coral Care Guide [4]
10. Melev’s Reef — Soft Coral Long-term Care Notes [5]
11. Reefkeeping Magazine — Soft Coral Husbandry Foundations
12. Reef2Reef — Soft Coral Garden Tank community thread [6]
13. Reef Builders — Xenia Boom-Bust Cycle
14. CoralRx — Coral Care Notes (soft coral handling) [7]