pest · saltwater tank

Aiptasia anemones

Aiptasia (glass anemones) are pest anemones that hitchhike in on rock or coral and reproduce rapidly. They sting coral, and large infestations dominate rockwork.

Reviewed by the Fast Aquatics husbandry team · Updated May 2026

Severity: Moderate - cosmetic + competitive with coral

Symptoms to look for

Brown or clear stalks with tentacles on rock
Stinging coral neighbors when expanded
Multiplying rapidly across rockwork

What causes it

Hitchhiked in on uncured live rock, frag plugs, or new coral.

Treatment options

Multiple effective treatments exist. Pick based on your tank type, livestock sensitivity, and severity. Always treat in a separate quarantine/hospital tank - most medications are toxic to coral, invertebrates, and live rock biology.

Berghia nudibranchs. Berghia nudibranchs eat ONLY aiptasia. Add 2-3 berghia per 50 gallons; they reproduce in tank. Best long-term solution.

Aiptasia-X or Joe's Juice. Inject directly into the aiptasia mouth with a syringe. Tank lights off, target one at a time. May need multiple treatments to fully eradicate large populations.

Peppermint shrimp. Lysmata wurdemanni (true peppermint) eat small aiptasia. Reliability varies; some shrimp ignore them.

Copperband butterflyfish. Will eat aiptasia but also picks at coral and is hard to keep alive. Last resort.

Prevention

Dip every new piece. Quarantine new rock for 4-6 weeks before placement.

Frequently asked questions

What does Aiptasia anemones look like?

Brown or clear stalks with tentacles on rock. Stinging coral neighbors when expanded. Multiplying rapidly across rockwork.

What causes Aiptasia anemones?

Hitchhiked in on uncured live rock, frag plugs, or new coral.

How is Aiptasia anemones treated?

Berghia nudibranchs: Berghia nudibranchs eat ONLY aiptasia. Add 2-3 berghia per 50 gallons; they reproduce in tank. Best long-term solution.

Can Aiptasia anemones be prevented?

Dip every new piece. Quarantine new rock for 4-6 weeks before placement.

How fatal is Aiptasia anemones?

Moderate - cosmetic + competitive with coral

Should I treat in the display tank or quarantine?

Always treat in a separate quarantine or hospital tank. Most medications are toxic to coral, invertebrates, and live rock biology.

Browse the full disease database for 45 aquarium conditions with treatment protocols, or check the care library for prevention-focused husbandry guides. Use our symptom matcher to rank likely diseases from observed signs, the water parameter checker to diagnose related water-quality issues, or the QT timeline calculator to plan a treatment schedule.