Carpet Anemones: Are they hard to keep?

are carpet anemones hard to keep

Carpet anemones, genus Stichodactyla, are such a joy to behold, especially when seen hosting a pair of clownfish.  They are however, one of the hardest types of anemones to keep and are only recommended for those with plenty of experience owning a saltwater aquarium.  In fact even some of the most experienced tank owners can struggle to keep carpet anemones successfully.

Research is key!  There are so many who dive in the deep end with no knowledge of what to look for in a healthy anemone, what to avoid, minimum tank size and so on. 

It is important to note that these anemones are renowned for eating other inhabitants of your fish tank, apart from clownfish.  They are best kept in an anemone only tank where you don’t have to worry about seeing your stock slowly disappearing. 

Below we’ll take a look at the three carpet anemones you’re sure to hear of in the reef-keeping trade and which are likely to host clownfish.  If the following puts you off buying a carpet anemone, why not take a look at this article which mentions other ‘easier-to-keep’ anemones that you may want to consider instead.

Carpet Anemone Types

Haddon's/Saddle Carpet Anemone (Stichodactyla Haddoni)

The Haddon’s Carpet anemone, is the easiest of the carpet anemones to look after.  They are also known as Saddle anemones due to the deep folds they create with their body which, you guessed it, look like a saddle. 

They require a deep sandbed of 2-3″ minimum and although they will find a rock, usually beneath the sand to attach to, they can also attach to the glass at the bottom of the aquarium.   

In the wild, if they feel threatened, they can retract completely under the sand.

Haddon’s carpet anemones are identified by their densely arranged small tentacles and tan coloured spots, called veruccae, on their large column.  Their tentacles are sticky to the touch.  

SIZE:  1.8ft (20 inches) approximately

SITUATION:  On the sand bed


FLOW:  Moderate to High



carpet anemone clownfish

Gigantea Carpet Anemone (Stichodactyla Gigantea)

The Gigantea carpet anemone prefers to attach to rock within the sandbed.  It is possibly the hardest of the carpets to keep alive, even for those with plenty experience in running saltwater aquariums.  

They are identified by dark verrucae which run up to the column and has longer tentacles than the Mertens or Haddoni anemones.  Their tentacles are also very sticky.  They have a very wavy appearance with deep folds.

Despite it’s name, Gigantea is not the largest of the Stichodactyla anemones.  This accolade belongs to Mertens anemone.  

SIZE:  1.8ft (20 inches) approximately

SITUATION:  Base of rock beneath the sand


FLOW:  Strong


SKUNK CLOWNFISH (A. perideraion)
A. rubrocinctus)

carpet anemone clownfish

Merten's Carpet Anemone (Stichodactyla Mertensii)

The Merten’s carpet anemone is not commonly available in fish shops.  This is more than likely snapped up as soon as they are put up for sale.  If they are available however, they are often mislabelled or simply called ‘carpet anemones’.

These carpets are the largest of them all and can grow to more than a metre in the wild.  It is distinguished by it’s more flattish oral disc and is of a more oval shape than the other two carpet anemones.  The verrucae are distinctive on the column as they extend to the base of the foot where they become striped.  The verrucae are also much brighter than those of the Gigantea or Haddoni with the column also being thinner than that of Haddon’s carpet anemone.  The tentacles are not sticky to touch like Haddoni and Gigantea.

SIZE:  3ft (36 inches) approximately

SITUATION:  Lower level of the tank on rock


FLOW:  Low to Moderate


SKUNK CLOWNFISH (A. akallopisos)

carpet anemone clownfish

How big do carpet anemones get?

ALL Stichodactyla grow very large, however the Merten’s Carpet is the largest.  It can grow to just over 3 feet.  They will very quickly outgrow small tanks.  

Gigantea and Haddon’s Carpet anemones grow to around 1.8 feet which is approximately 20 inches.  

Minimum tank size

Carpet anemones have a high bioload which can often exceed a smaller tank’s capabilities.  The larger the system, the easier it is to keep the tanks parameters stable and therefore your anemone happy.

The following is a guide to the minimum tank size for each anemone however, the bigger the better.  A Mertens anemone would be very happy in a 125 gallon aquarium for example.

Haddon’s/Saddle Anemone:  75 gallons

Gigantea Anemone:  75 gallons

Merten’s Anemone:  100 gallons 

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Lighting Requirements

All three of the carpet anemones mentioned above need strong lighting.  Although it is uncertain exactly what PAR is needed, any of the following should be suitable to satisfy their lighting requirements:

– LEDS such as Ecotech Radion, AI Prime and Red Sea ReefLEDs

– T5 light fixtures and/or Hybrid Lighting

– Metal Halides

Tank Preparation

Before buying a carpet anemone, you will need to ensure that you have a quarantine tank set up.  Like any fish or invertebrate, anemones should also be quarantined prior to being added to your display tank to ensure that they are fighting fit and clear of any parasites or diseases that could be passed on to your other tank inhabitants.  If you would like to know more on setting up a quarantine tank, here is an article telling you how.  

Remember to cover all powerheads, wavemakers and heaters as anemones can move around the tank whilst find their ‘perfect’ site.  While doing so they can find their way into powerheads and wavemakers or end up burning themselves on exposed heaters.  At worst, they will end up shredding themselves and releasing deadly toxins into the water column, affecting all fish and coral.

What to look for when buying a carpet anemone

As with any anemone, it is imperative to check that they are healthy before you take them home.  An anemone that is not healthy to begin with greatly reduces it’s chances of survival especially considering the stress through the journey from it’s current tank to your own.  

The following can indicate an ill or stressed anemone:

  • A gaping mouth.  Mouths should be closed.

  • A drifting anemone.  The foot of the anemone should be firmly attached to either rock or the tank glass itself.   

  • A white anemone.  A carpet anemone that is bleached has lost it’s zooxanthellae and it can take months for it to regain them.  This is a definitely a sign that they are either ill or severely stressed.

What to do when introducing an anemone to your tank

Make sure to fully acclimate your anemone before adding it to your quarantine or display tanks.

When you are ready to add the anemone to your quarantine tank and eventually your display tank, lower the lighting and flow in order to allow the anemone to gradually adjust to it’s new surroundings.  These can gradually be increased over the next couple of weeks.

It is best to wait until the anemone has adjusted to the new tank before feeding.  If it has taken hold and it is generally looking healthy, then you can start feeding it small pieces of meaty food once every week or two.

Help! My carpet anemone is shrinking!

You may notice a carpet anemone shrinking or looking deflated when you place it in your tank.  Whilst this can be a sign of it settling in and trying to establish a foothold, it can also be a sign that it needs help.   

Keep a careful eye on it but if it does not inflate again after a week, then it is highly recommended that the anemone be placed in a quarantine/hospital tank and treated with Cipro.

How do carpet anemones eat?

Anemones will use it’s stinging tentacles to grab and paralyze it’s prey.  It will then fold parts of it’s body around the food as it moves it towards it’s mouth.   

Here is a cool video of a carpet anemone being fed:

Feeding – What do carpet anemones eat and how often?

As carnivores, anemones live on a diet of meaty foods.  They can be fed clam, mussel, shrimp etc.  

A word of warning regarding silverside however.  It has been reported to have been the cause of the deaths of both Haddons and Gigantea anemones.  They should only be fed good quality foods which are invariably more expensive.  Cheaper foods have been known to kill anemones due to being inferior in quality and having bacterial infections. 

Carpet anemones should be fed at least once every week or two.  Overfeeding will result in them expelling any excess which will end up fouling the tank.

Do carpet anemones move?

In general, if the flow and lighting is good, they are happy and unlikely to move.  If they are not however, they will move to find a better place to settle.  This is why it is advisable to have the tank housing carpet anemones without coral.  If they venture too close to any coral they will end up stinging them which could result in the coral never recovering.

Remembering that Gigantea and Haddoni prefer sand, it wouldn’t be a good idea to place them on rock.  They will definitely wander in search of sand.  And vice versa with a Merten’s.  They prefer rock so if placed on the sand, they will try and find rock in order to attach itself to.  


Carpet anemones can be amazing to keep and watch grow.  Just remember to have a mature saltwater aquarium with stable parameters.  Do your research before buying a carpet anemone and know whether the anemone you want is as healthy as possible by looking for the signs mentioned above.  

Hopefully you have found this article informative and if there are any other topics you’d like me to cover, just let me know by contacting me either on Facebook or via the Contact tab at the top of the page. 

Hi, my name is Craig.
I am the owner of The Salty Side.
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