Heteractis

Heteractis are large, impressive host anemones that include some of the most sought-after clownfish hosts in the hobby. The most commonly kept species are Heteractis magnifica (magnificent anemone or ritteri) and Heteractis crispa (sebae anemone). These are expert-level animals that require a mature, stable reef system — at minimum twelve months old with proven parameter stability. Provide strong PAR (250–400+ PAR) and moderate flow. Maintain pristine water: alkalinity 7.5–9 dKH, calcium 400–450 ppm, temperature 25–27°C, and near-zero ammonia and nitrite. These anemones are not suitable for beginners.

Heteractis magnifica in particular has a reputation as one of the most challenging anemones to keep long-term. They demand intense lighting, pristine water quality, and consistent conditions. In the wild, they are found in high-light, high-flow reef environments and can reach over 50 cm across. Like all anemones, Heteractis will wander until they find suitable conditions, stinging and killing corals in their path. They can move into powerheads, overflows, or across your most prized coral colonies. Protect all pump intakes and accept that you cannot control their final placement. If a Heteractis is consistently wandering, conditions are likely not meeting its needs.

Heteractis are photosynthetic but benefit significantly from weekly target feeding with meaty foods. They host a range of clownfish species — H. magnifica is particularly popular with Ocellaris and Percula clowns, both of which are native to Australian reefs. Australian-sourced specimens from the GBR region are preferable. Propagation is through natural splitting, which occurs rarely in captivity. These anemones should only be attempted by experienced reefers with dedicated systems or large tanks where wandering poses minimal risk to other livestock.