Like a palm tree from hell, Aiptasia anemones attack even the most protected saltwater aquariums. Sooner or later, your journey into the underwater universe of reef tanks will put you face-to-face with the swaying tentacles of this aggressive anemone. Okay, that may seem overly dramatic. However, if you’ve ever encountered the mesmerizing beauty of these harmful pests, you understand the need for dramatics. I’ve witnessed the damage of an Aiptasia outbreak in far too many tanks. Like a pervasive virus, these ancient organisms silently enter reef tanks and disrupt the delicate balance required to maintain a thriving ecosystem. Whether you’re battling an army of Aiptasia in your current tank, or want to prepare for the inevitable invasion, let’s take a journey into the alien world of Aiptasia anemones.

As a lifelong aquarist, Yuliya has an endless curiosity about our underwater universe. After graduating with a bachelor’s in Environmental Engineering, she transformed her passion into a successful career. While working at the Institute of Environmental Protection in Moscow, her passion for saltwater and reef aquariums only increased. Moving to the United States in 2013, Yuliya embarked on another impactful journey by sharing her unprecedented experience for all aquarium hobbyists ... Read More .

Aquarists describe Aiptasia as creepy parasites to hauntingly beautiful organisms. I describe them as unwanted, demanding and deceptively attractive houseguests. Imagine waking to the sound of an uninvited visitor rummaging through your kitchen. Eating your entire stash of potato chips, you ask this handsome guest how he got into your home. “Oh, I walked in with your new roommate,” he replies between bites. You look over and your roomie explains he didn’t know anyone was with him. You want to kick your new roommate out for bringing in a pest, but you need him to pay your rent. So, instead, you try to get rid of the unwelcome hitchhiker. Nothing works. As soon as you push him out the door, he’s magically sitting on your couch finishing off the last bite of cake. It seems no matter what you do, this invasive houseguest appears invisible. As crazy as this scenario seems, it’s exactly what dealing with an Aiptasia anemone is like. But why? To understand how this pest infiltrates your reef tank, the first step is understanding what it is. Classified as a symbiotic cnidaria, Aiptasia is a common organism found in tropical seas. Unlike other creatures born out of the warm tropical oceans, Aiptasia can survive in a wide array of water quality conditions and water salinities. Its adaptable nature means it can thrive in a variety of saltwater tanks. If you’ve ever witnessed an Aiptasia outbreak, then you’ve likely noted how quickly it propagates. This is due to its unique reproduction ability. While most invasive species reproduce sexually, Aiptasia multiplies both sexually and asexually. This means, even without a partner, this anemone spawns “children” from itself. In fact, to create a new Aiptasia, only a single cell is needed. Have you ever wondered why your infestation never goes away? The answer is likely due to extermination methods. Microscopic damage, which sends off even a single cell into your tank is enough to repopulate the species. Along with its naturally rapid reproduction, saltwater aquariums are perfect breeding grounds for Aiptasia. The carefully balanced reef tank water chemistry and ample light required to sustain life in your self-contained ecosystem is literally paradise for this pest.

The Appearance of Invaders - What Aiptasia Look Like?

Also known as Glass, Tube or Rock anemones, Aiptasia’s aren’t difficult to identify. In essence, these pests look like underwater palm trees. The polyp body, which is the “trunk” of the anemone, attaches to a circular disk. Its waving branches are actually stinging tentacles.



Specific characteristics vary based on its species. For example, some Aiptasia species are clear while others feature earth tone coloration. The majority of saltwater aquarium Aiptasia’s are brownish-tan and range from barely noticeable to several inches long.

The Duality of Danger - Difference Between Aiptasia and Majano Anemone.

Identifying Aiptasia species isn’t difficult. Their small, stringy tentacles are a dead giveaway. However, this isn’t the only invasive anemone capable of invading your tank. The Majano anemone may appear similar, but its threat to your tank requires special attention.



Majano anemones are often larger and typically feature brightly colored designs. While they also have tentacles, they aren’t thin and stringy. Instead, its tentacles are club-shaped and are notoriously difficult to get rid of.



If you’re in doubt of the type of anemone in your tank, send us a picture and we’ll gladly help identify your uninvited guest.

No Good Deed Goes Unpunished - How Aiptasia Anemones Enter Your Tank.

Unless you’re one of the few quirky aquarists who appreciate invasive species, you certainly didn’t outright purchase an Aiptasia colony, or so you thought.



While you assumed the live rock or coral you carefully selected would bring balance and beauty to your saltwater aquarium, little did you know you were also bringing in a plague. Aiptasia anemones enter your tank by hitchhiking inside of live rocks or along the bottom of a frag plug of your new coral.



Unfortunately, these pests are excellent at hiding. When disturbed or threatened, they instantly retreat into the tiny holes located throughout a live rock. Masters of patience, Aiptasia colonies can remain inside their burrows for weeks or even months. By then, it’s too late. The rock or coral is happily living in your reef tank.

Why Evict Aiptasia Anemones From Your Tank?

The most common question asked about Aiptasia anemones is whether it kills fish and/or corals? In short, yes, but maybe not in the way you’d assume.



The biggest threat posed by Aiptasia is twofold. Its rapid reproduction often leads to overtaking the surface of rocks, which can make your tank as overcrowded as an NYC subway train during rush hour. However, the real harm comes down to its stinging tentacles. When threatened, venomous cells eject from its tentacles. The poison is capable of killing sensitive corals should they come too close to the Aiptasia’s turf.



What about fish? Is it possible for an Aiptasia to fatally harm the swimming inhabitants of your tank? While the damage from its sting isn’t powerful enough to kill larger fish or invertebrates, smaller creatures are no match for its territorial attack.

The Secret Life of an Aiptasia Assassin - Home Remedies of Death.

As you can see, the swaying branches of this underwater palm tree aren’t to be taken lightly. So, how do you kill an asexual organism capable of spawning new generations with a single cell? This answer has plagued countless aquarists since the dawn of saltwater aquariums.



The most notable issue with killing Aiptasia is doing so without compromising its physical integrity. As we’ve discussed, the smallest abrasion can release reproductive cells throughout your tank. Moreover, these masters of survival retreat into live rock holes at the first sign of danger.



Needless to say, you can’t simply reach in and grab them. However, aquarists have concocted numerous extermination methods designed to kill Aiptasia anemones in as little effort as possible. How, you may ask? By injecting a variety of substances found in your home directly into the anemone.



So, do these home remedies work? While some are more fiction than fact, there are several worth mentioning. These include:

For each method you should turn your flow OFF for 5 mins. before and during the treatment and wait 15 mins. before turning it back ON after the the treatment, including the return pump.

Lemon Juice - Instead of reaching for your bottle of lemon juice to enhance your glass of water or cup of tea, maybe try it as an Aiptasia exterminator. While wearing gloves, fill a syringe with pure lemon juice and inject it directly into the Aiptasia. Make sure to move slowly to prevent scarring the anemone into its hole.

Hydrogen Peroxide - Just like with the lemon juice, fill a syringe and carefully inject a small amount of the solution directly into the disk of the Aiptasia. Be extra careful to not release any hydrogen peroxide into the tank. Not the safest way.

Kalkwasser - Also known as Calcium Hydroxide, kalkwasser is capable of killing Aiptasia. However, I don’t recommend this extermination tactic. In order to work, you must precisely fill the Aiptasia with a concentrated dose. If you try killing too many in this way, you can inadvertently raise your tank pH level, which is no good.