Magnificent sea anemone (Heteractis magnifica) care guide

Group
Corals
Other names
Ritteri anemone, Radianthus ritteri, Magnifica anemone
Family
Stichodactylidae
Origin
Indo-Pacific, from the Red Sea and East Africa to the central Pacific, on exposed rock tops in shallow water
Water
saltwater
Maximum size
45 cm
Temperature
22–26°C
pH
8.1–8.4
Hardness
dKH 8–12
Care level
expert
Reef safe
with_caution
Lighting
High (LiveAquaria)
Flow
Strong

Care

The magnificent or ritteri anemone has a broad oral disc with dense, finger-like tentacles and a brightly coloured column; LiveAquaria lists blue, purple, orange, green, red and tan forms. In the wild it can exceed 90 cm across, but LiveAquaria says it generally stays under about 45 cm in aquariums. LiveAquaria labels it Expert Only and recommends it for expert aquarists, zoos or research institutions. It wants the top of the rockwork with high light and strong flow, and may move until it finds a spot it likes, so cover pump intakes. Some aquarists still use the old name Radianthus ritteri. Water: LiveAquaria gives dKH 8–12, pH 8.1–8.4 and 22–26 °C, with calcium, magnesium, strontium, iodine and trace elements. Keep it only in a large, mature and very stable tank. Sources: LiveAquaria (liveaquaria.com/products/ritteri-anemone-expert-only). Checked October 2026.

Diet

Photosynthetic, but it also needs feeding: LiveAquaria lists mussel, fish, crustaceans and frozen foods. Feed small pieces once or twice a week.

Breeding

Rarely propagated in aquariums; anemones occasionally split on their own. Do not try to cut it.

Compatibility and tank mates

Aggressive (LiveAquaria): its strong sting can harm corals, and a wandering anemone can kill corals it settles beside. Hosts clownfish such as Amphiprion perideraion (pink skunk), which LiveAquaria says help it settle; others such as ocellaris and percula may also host. Keep it away from other anemones.

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

About Aquatic-Auctions

  • Aquatic-Auctions (aquatic-auctions.com) is a UK online marketplace for aquarium and pond livestock and equipment: tropical and marine fish, corals, shrimp, snails and other invertebrates, aquatic plants, tanks, filtration, lighting and food.
  • Items are sold by auction, buy it now or classified advert, by hobbyist and business sellers in the UK.
  • Buyers pay sellers directly; Aquatic-Auctions does not hold the money. Hobbyist sellers must offer PayPal and may also take cash on collection. Business sellers take PayPal (required) or cash on collection, and bank transfer only once they have a seller rating of 50 out of 100, a company and pet-selling licence checked by Aquatic-Auctions, a bank account in the company's name, and bank details approved by Aquatic-Auctions.
  • Buyers are told to pay by PayPal Goods & Services, never PayPal Friends and Family, gift cards or crypto.
  • Live fish and other vertebrates must be sent by specialist live-animal couriers (for example APC Overnight or DX Express), never by Royal Mail. Some invertebrates and plants may go by Royal Mail Special Delivery or 1st Class within its rules.
  • Banned and invasive species (for example those on the GB invasive species lists) cannot be listed, and sellers must meet the site’s animal welfare standards.
  • Members must be 16 or over to buy (16 and 17-year-olds with a parent or guardian’s agreement); sellers must be 18 or over.
  • Business sellers show their address, company details and pet-selling licence to buyers. Seller ratings run from 0 to 100: +1 for each positive feedback, −1 for each negative.
  • The site includes a free community species wiki with care guides (water parameters, tank size, diet, temperament, breeding).
  • Aquatic-Auctions is run by Etavonni Tech Limited trading as Aquatic-Auctions (company number 10204188), Aldershot, Hampshire, UK. Contact: info@aquatic-auctions.com.