Eliminating Aiptasia Anemones From Saltwater Aquariums

Aiptasia sea anemones can overpopulate your reef tank after they sprout out of living rock. Simply pulling them out only leads to a population explosion as each piece can grow into another anemone.

The solutions to remove them include chemical methods, introducing predators, and osmotic shock. Learn the pros and cons of each of these solutions.

Ways to Kill Aiptasia Sea Anemones

One way to kill aiptasia sea anemones in a saltwater aquarium is by injecting them with one of the below chemical or liquid solutions. When using this method, you should inject the solution of choice directly into the stem of the anemone with a needle and syringe. If working with a caustic chemical, it is wise to wear protective eye goggles and gloves as a precaution.

Bottled Lemon Juice Concentrate

Inexpensive bottled lemon juice gives immediate results. It is safe for a reef tank and easy to do. Give lemon juice injections of 0.5 ml to the base of each anemone using a syringe.

Sodium Hydroxide

When using this chemical for injection, it can be mixed strong enough for a certain kill. Removing the rock from the tank and dribbling the sodium hydroxide solution over the anemone gives a 100 percent mortality rate. When having to get to an anemone that has its foot embedded in a crevice, the mortality rate is only about 50 percent. This is due to having to guess where to put the solution and not getting it on the correct spot.

Calcium Hydroxide

Injecting aiptasia with calcium hydroxide (kalkwasser) in a concentrated solution is one of the most common methods used. The consensus is that it does work, but is not very efficient unless done properly. The kill rate is low if the calcium hydroxide is not directly injected into it and if the solution is not strong enough. Another problem is that if you try to kill too many aiptasia at once, it can cause a problem with the pH level in your tank by adding too much calcium hydroxide at one time.

Hydrogen Peroxide

When injected into aiptasia anemone, hydrogen peroxide kills it fairly quickly.

Using Predators to Kill Aiptasia Anemones

In the quest to find a natural way to eliminate aiptasia anemones from saltwater aquariums, some marine animals have been found that will devour the pesky aiptasia with pleasure. However, before you decide to introduce such a fish, shrimp, nudibranch, or other animals into your aquarium, consider the cons as well, especially in reef tank systems:

• Most of the fish suggested will pick at and eat various types of soft and stony corals, zoanthids, sea mats, and polyps.
• Many of the predators naturally feed on various types of both sessile and motile invertebrates, such as other sea anemones, feather dusters, and other tube worms, clams, sea urchins, and crustaceans. Those that may not eat them initially, once all the aiptasia have been consumed, in all likelihood will search for alternative food sources such as these as well.
• Some species are sensitive and difficult to care for in captivity, primarily due to specialized diet requirements, if you are not an experienced aquarist, the animals will very often starve to death.
• Individual specimens may vary in their desire to eat the aiptasia, and the size of the anemones may be a factor, too. Therefore there is no guarantee any particular animal will definitely eat them.

The Natural Predators of Aiptasia Anemones

For the above reasons, caution is advised when deciding to add any of these most commonly suggested animals to your aquarium for eradicating aiptasia anemones:

• Butterflyfishes: Auriga (Chaetodon auriga), raccoon (Chaetodon lunula), Klein's (Chaetodon kleini), long-nosed (genus Forcipiger species), teardrop (Chaetodon unimaculatus), and copperband (Chelmon rostratus).
• Filefishes: There are four species of genus Acreichthys filefishes, but the bristle-tail filefish (Acreichthys tomentosus) from the Indo-Pacific region is said to be the ultimate choice aiptasia eater.
• Puffers: The brown whitespotted or guinea fowl puffer (Arothron meleagris) may eat aiptasia, but it grows to a very large size. Therefore the tobies or sharp-nosed species of the Canthigastrinae sub-family might be more suitable.
• Shrimps: The "true" peppermint shrimp (Lysmata wurdemanni) is by far the top choice of aquarists for eating aiptasia anemones, but the trick with this one is making sure you get the right species. Although the camelback shrimp (Rhynchocienetes uritai) is very often misrepresented and sold as a true peppermint shrimp, it is the L. wurdemanni species that usually preys on aiptasia anemones, whereas the R. uritai will most likely ignore them. It should also be noted that Lysmata californica is also called the peppermint shrimp, but is endemic to the west coast of North America, and does not consume aiptasia (it also does not do well in an aquarium which is heated above 60 F).
• Hermit crabs: Almost always reef safe, and beneficial algae eaters as well, in particular, one or two of the more common red-legged or white-spotted hermit crabs (Dardanus megistos) might do the trick.
• Nudibranches: Berghia sea slugs are by far the most popular choice because they are 100 percent safe and effective when used and cared for properly. These nudibranches solely eat aiptasia, and will die without them present, which means you have to take steps to ensure their survival.

Hyposalinity and Other Remedies

If you have concerns about adding any of these animals to your aquarium, there is always the option to get rid of aiptasia using osmotic shock therapy (OST), or hyposalinity. This is easy to do, and works quite well, but is not for use in reef tank systems.

There are over-the-counter remedies as well that are specifically designed to target and kill these anemones and are also said to be reef-safe products.