Zoanthids (Zoanthus spp.) care guide

Group
Corals
Other names
Zoas, Colony polyps, Button polyps, Bowzer, Rasta, Eagle Eye, Utter Chaos, Fruit Loops, Radioactive Dragon Eye, Purple Hornet
Family
Zoanthidae
Origin
Tropical seas worldwide, on shallow reef flats and rock
Water
saltwater
Temperature
24–27°C
pH
8–8.4
Hardness
dKH 8–10
Care level
beginner
Reef safe
yes
Lighting
Low to moderate; about PAR 80–150 (Top Shelf Aquatics)
Flow
Moderate, indirect

Care

Zoanthids are colonial polyps that form carpets of small, button-like polyps, each with a coloured centre (the oral disc) and a ring of short tentacles (the skirt). Hundreds of named captive-grown morphs are traded, such as Bowzer, Rasta, Eagle Eye, Utter Chaos and Fruit Loops. Top Shelf Aquatics and LiveAquaria both rate them easy. Place them low to middle on the rockwork, ideally on an isolated rock island to contain their spread (Top Shelf Aquatics), with moderate, indirect flow to keep detritus off the mat. Top Shelf Aquatics suggests acclimatising them to light over two to three weeks to avoid bleaching, and blue-heavy lighting for colour. Water: Top Shelf Aquatics recommends 24–27 °C, pH 8.0–8.4, salinity 1.025–1.026, alkalinity 8–10 dKH, calcium 400–450 ppm, magnesium 1,250–1,350 ppm, nitrate 2–10 ppm and phosphate 0.02–0.08 ppm. LiveAquaria suggests regular iodine and trace elements. Very low nutrients often make them recede. Growth is fast; they spread by budding and runners. Pests: watch for zoa-eating nudibranchs, sundial snails and spider crabs, and for zoa pox (tan or white pustules). Dip and quarantine new frags. Safety: zoanthids and palythoa contain palytoxin, a dangerous toxin. Wear gloves and eye protection when handling or fragging them, and never boil or scrub rock carrying them. Sources: LiveAquaria (liveaquaria.com/products/colony-polyp-zoanthus-corals); Top Shelf Aquatics (topshelfaquatics.com/pages/corals/bowzer-zoanthids-coral). Checked October 2026.

Diet

Mainly photosynthetic. Top Shelf Aquatics says fine foods such as zooplankton, phytoplankton or powdered coral food once or twice a week improve polyp fullness; LiveAquaria recommends micro-plankton or baby brine shrimp if lighting is poor.

Breeding

Easy: cut a group of polyps off the rock with a scalpel or bone cutters, or snip runners, and glue the base to a plug with cyanoacrylate gel. Frags spread across the plug in a few weeks. Wear gloves and eye protection throughout (see the palytoxin warning).

Compatibility and tank mates

Generally peaceful but listed as semi-aggressive: they can overgrow slower corals, and LiveAquaria notes they can sting neighbours. Leave 5–10 cm to other corals. Some angelfish and butterflyfish eat them.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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