Zoanthid Coral Care Guide (Zoas & Palys)
Zoanthids — affectionately called “zoas,” with their larger cousins known as “palys” (Palythoa) — are colonial polyp corals that come in a jaw-dropping rainbow of colors and patterns. They’re one of the hardiest, fastest-spreading, and most beginner-friendly corals in the reef hobby, which is exactly why they’re so collectible. A single frag can carpet a rock over time, and a mixed “zoa garden” is one of the most eye-catching displays you can build. This guide covers lighting, flow, placement, parameters, feeding, pest prevention, an important safety note, and how to acclimate your new colony.
Zoas vs. Palys: What’s the Difference?
Both are colonial button polyps cared for the same way. Zoanthids (Zoanthus) tend to have smaller polyps and are connected by a thin mat, while Palythoa polyps are usually larger and embedded in a thicker, sandy tissue mat. For care purposes you can treat them identically.
Care Level: Excellent for Beginners
Zoanthids are among the most forgiving corals available. They tolerate a wide range of conditions, grow quickly, and bounce back from minor mistakes. Their main challenges are hitchhiking pests and knowing that “closed for a few days” is usually nothing to panic about.
Quick-Reference Care Parameters
| Coral type | Soft / colonial polyp |
| Care level | Beginner |
| Lighting | Low–Moderate · PAR 50–150 (color pops ~75–125) |
| Flow | Moderate, random |
| Placement | Low to mid; rock or sandbed |
| Temperature | 76–82°F (ideal ~78°F) |
| Salinity | 1.024–1.026 (~35 ppt) |
| Alkalinity | 8–11 dKH |
| Calcium | 400–450 ppm |
| Magnesium | 1250–1350 ppm |
| Nitrate | 2–10 ppm |
| Phosphate | 0.03–0.10 ppm |
| Feeding | Optional · micro-foods 1–2× per week |
| Aggression | Low sting, but spreads and competes chemically |
Lighting
Zoanthids are highly adaptable and will live under almost any reef light, but color is king with these corals. Most zoas show their best color in the PAR 75–125 range. Too little light and they stretch tall and fade; too much and they can brown out or bleach. If you move a colony to a brighter spot, do it gradually. Blue-heavy spectrum makes their fluorescent pigments pop.
Water Flow
Give zoas moderate, random flow. Good water movement keeps detritus from settling on the polyps (a common cause of them closing up) and discourages pests and nuisance algae. Avoid a direct, blasting jet, which will keep them closed; aim for turbulent, indirect flow that gently ruffles the polyps.
Placement
Zoanthids do well anywhere from the sandbed to the mid rockwork. Start a new frag lower in the tank and move it up over a couple of weeks if you want more light. Because zoas spread and can overtake slower neighbors — and wage low-level chemical warfare — leave open rock around a new colony and run activated carbon to keep the water clean in a mixed reef.
Water Parameters
Zoanthids aren’t heavy calcifiers, so they’re undemanding on alkalinity and calcium, but they still reward stability. Keep temperature and salinity steady, alkalinity in the 8–11 dKH range, and a small amount of nutrient in the water — zoas often color up best in tanks that aren’t scrubbed ultra-clean (nitrate 2–10 ppm, phosphate 0.03–0.10 ppm).
Feeding
Zoanthids get most of their energy from light but respond well to occasional feeding. Once or twice a week you can target-feed fine particulate foods — powdered coral food, reef roids, baby brine, or phytoplankton — by gently wafting it over the open polyps. Feeding is optional and best done in low flow so the food isn’t swept away.
⚠️ Important Safety Warning: Palytoxin
Zoanthids and especially Palythoa can contain palytoxin, one of the most potent natural toxins known. This is a real hazard, not a scare — take it seriously:
- Always wear nitrile gloves and eye protection when fragging, scraping, or handling zoas, and never handle them with an open cut.
- Never boil, bake, or dry-scrape rock with zoas/palys on it — heat and aerosolizing the toxin can cause serious respiratory poisoning.
- Frag in a dedicated container, wash hands and tools thoroughly afterward, and keep pets and children away.
Common Problems & Pests
- Colony stays closed: usually detritus on the polyps, too much or too little light/flow, a parameter swing, or new-frag stress. Improve flow, check parameters, and give it several days.
- Zoa-eating pests: zoa-eating nudibranchs, sundial snails, and “zoa spiders” can wipe out a colony. This is why a coral dip on arrival is essential (see below). Inspect closed or shrinking colonies closely.
- Melting / rapid loss: can follow a pest outbreak or a bad parameter swing. Dip, remove affected polyps, and stabilize conditions.
How to Acclimate Your New Zoanthids
- Temperature match (15–20 min): With lights dimmed, float the sealed bag in your tank to equalize temperature.
- Drip acclimate (20–40 min): Open into a clean container and drip tank water in slowly until the volume roughly doubles.
- Coral dip (recommended): Dip in a reef-safe coral dip per directions to remove hitchhiking pests, then rinse in clean saltwater. Zoas are pest magnets, so don’t skip this step. Wear gloves.
- Placement: Set the frag low in the tank in moderate flow and moderate light, away from corals it could overgrow.
- Let it settle: Don’t worry if the polyps stay closed for a day or two — that’s normal transit behavior. They’ll open as they adjust.
Frequently Asked Questions
Are Zoanthids good for beginners?
Yes — they’re one of the best beginner corals: hardy, colorful, fast-growing, and inexpensive to start collecting.
Why are my zoas closed up?
Most often it’s detritus settling on them, a direct flow stream, a parameter swing, or simple new-frag stress. Improve flow, confirm stability, and give them a few days before worrying.
Do I really need gloves?
Yes. Palytoxin is a genuine hazard. Gloves and eye protection when handling or fragging, and never heat rock with zoas on it.
What is WYSIWYG coral?
WYSIWYG means “What You See Is What You Get” — the exact colony in the photo is the one shipped to you.
Shop WYSIWYG Zoanthids & Coral Care Guides
Browse our current live coral for sale for this week’s hand-selected WYSIWYG zoa and paly colonies. For more species, see our full library including the Hammer & Frogspawn (Euphyllia) Care Guide, the Goniopora Care Guide, and the Cynarina Care Guide.
