The Salty Side: Saltwater Aquariums for Beginners

Are Anemones Hard to Keep?

Sea anemones (Actiniaria) are invertebrates, as are snails, shrimp, starfish, sea urchins and jellyfish.  This simply means that they have no backbone and are in most cases, soft bodied within.  They therefore need a way of protecting themselves and this can come in the form of stinging tentacles, shells or spikes for example.  So, are anemones hard to keep?

Anemones use their stinging tentacles to catch and paralyze their prey.  They do this by injecting them with a neurotoxin.  And it is this neurotoxin, amongst other reasons, that reefers might be wary about when thinking of purchasing an anemone for their saltwater aquarium.  Not only that but can they catch and kill fish but also sting coral when on the move. 

Research is vital when looking at what anemone to add to your saltwater aquarium.  Below I have answered some of the most popular question people ask about anemones.

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Are anemones hard to keep?

It depends on what type you want to keep.  Some can be really difficult to keep as they require specific water parameters, flow and lighting, such as carpet anemones, and others aren’t as fussy like bubble tip anemones.  Some will eat your fish (they don’t care how expensive they were!) whilst most end up stinging coral as they move about the tank searching for a new places to settle. 

It is a personal choice as to whether or not you’d like to take on an anemone.  They can look amazing in a tank and particularly so when hosting a pair of clownfish.  The main consensus is that your tank is large enough that it can provide stable parameters and allow the anemone space to grow. 

This article covers general requirements for most anemones, however carpet anemones have specific requirements.  They have an entire article dedicated just to them here:  Carpet Anemones 

Anemone requirements

Tank Age

Anemones require a stable environment so should not be added to a tank unless it has been running for at least 6 months.  However the longer the better.  A mature aquarium will give the anemone the best chance of survival and will not stress it out any further.  They have quite an adjustment to make settling into a new tank.

Tank Size

It is recommended that anemones are kept in tanks that are larger than 40 gallons as the smaller the tank, the less stable it is.  That’s not to say you cannot keep any in a smaller tank but it may not be as successful as it will require a lot more work and consistency in keeping the environment stable.

The other issue with a smaller tank is that they can grow extremely large.  They may not be large when you buy them but some bubble tips can end up being 18 inches in width. 


Make sure to cover wave makers, intakes, overflows and heaters situated inside the display tank so that if your anemone does go wandering, it will not do itself, or anything else in the tank, any harm.


Anemones like rocks that have holes and crevices that they can reach their foot down into to secure themselves.  Some, such as the Sebae, live on the sand but still need a rock to attach their foot to.


Lighting:  100 – 200 par

Alkalinity:  8-11 dKH

Salinity:  1.026 sg/35ppt

Temperature:  77 – 79 degrees F

Calcium:  375 – 425

Magnesium:  1300ppm

Nitrate:  <10 ppm

Phosphate:  .03ppm

Choosing a healthy anemone

Doing these basic checks will save you time, money and disappointment.  Many who are new to this hobby don’t think about checking to see if the fish/invertebrate/coral they are purchasing are in a healthy condition. 

  • Mouths should not be gaping open.  This is a definite sign that something isn’t right.

  • Anemones should be maintaining a strong foothold onto whatever they are clinging to. If they are floating around the tank it could mean they are wandering but unfortunately it also means that they may not be well.

  • Be wary of white anemones.  Often this means that it is stressed either due to lighting, water movement or water quality.  Many do not recover.

What lighting do anemones need?

Most lighting is effective.  Some reefers use Metal Halides, others use LED or T5’s.  It’s a matter of personal choice but the important thing to remember is that it should be providing between 100 – 200 par. 

Do you have to feed an anemone?

Yes.  Although anemones will grab food when feeding the other inhabitants of your tank, they also require target feeding every couple of weeks.  This is to ensure that they are getting the food and nutrients they need and not just hoping that they have managed to catch some food whilst feeding the other fish and inverts in your tank.

Do not overfeed however.  The anemone will open it’s mouth and pour everything out again, polluting the tank.

What to feed an anemone

You can feed your anemone frozen foods such as mysis or krill.  Any meaty foods will do.  This can be target fed with a turkey baster or syringe.  Just make sure you don’t get stung when getting close!

They can also be fed small chunks of clam, squid, mussel etc.

Do you need to acclimate an anemone?

Yes!  When either placing an anemone in quarantine or display tank, they must be drip acclimated, just as you would invertebrates.  For more information on how to drip acclimate, see this article.  They are extremely sensitive to changes in their environment and therefore needed to be transitioned to the new tank slowly and with care.

When can you add an anemone to a tank?

As mentioned above, anemones can be added to an aquarium once the tank has matured and normally this is at least more than 6 months.  Leaving it for a year is even better.

What to do when adding an anemone to your tank

When you are ready to add your anemone to your main tank, it is recommended that the lighting and flow be reduced.  Over the next 2 – 3 weeks, this can gradually be increased giving your anemone a chance to settle in gently.

The anemone might move around for a bit until it finds it’s happy place. 

What is the easiest anemone to keep?

The easiest anemones, especially for beginners, are maxi mini and rockflower anemones.  They are bright and colorful and pretty much stay where you put them.  They are also not as fussy as some of the other anemones, such as hetractis anemones.  However the mini carpet does have quite a big downside in my opinion.  More on that below.  

I’ve mentioned three of the most popular anemones and a bit more about them:

Rockflower Anemone

Rockflower anemones (Epicystis crucifer) originate from the Caribbean.  They are popular due to their bright colours under blue lighting as well as being relatively easy to care for.  They’re not as fussy on water quality and water movement as some anemones are.  Lighting doesn’t appear to be much of an issue either.

Rockflowers have a symbiotic relationship with the Pedersons anemone shrimp so you might consider getting.  They eat any frozen foods such as mysis or krill which is great as the majority of reef keepers feed their fish frozen foods anyway.

A note on rockflowers … they will split and reproduce through spawning so you may end up with more than you started with.  They can also eat smaller fish.

Mini Maxi Carpet Anemone

Mini Maxi anemones grow to about 4 – 6 inches and are great for beginners HOWEVER they have been known to eat fish such as Clownfish and other fish, especially if in a smaller tank.  

Similar to the rockflower, they are also easier to keep and do well in lower lighting.  Originally from Vietnam, these anemones do not host fish like some of the other anemones available but do host shrimps like the Sexy Shrimp (Thor amboinensis).

Like other anemones, they will sting coral if they get too close.  Care is also needed when handling them as they do cause considerable pain if they happen to catch the inside of your arm.

Bubble Tip Anemone

Bubble Tip Anemones (Entacmaea quadricolor) are probably one of the most popular anemones on the market.  This could be due to the fact they can split fairly regularly.  Their bubble tips can be a bit hit and miss with a lot of speculation as to what and what doesn’t make them appear.

They can split fairly regularly so you will more than likely end up with more than one in your saltwater aquarium.  

Bubble Tips are not true hosts of clownfish but they do host them.  They are also more likely to host any clownfish rather than one or two specific varieties like some other anemones.

They like lighting on the stronger side (increased gradually from when you first put them in the tank) and a relatively strong flow.

Can you have two anemones in a tank?

Yes, you can have more than one anemone in a tank.  But it really does depend on what anemones they are.  Reefers have successfully kept different types of Bubble Tip anemones (BTA) in the same tank.  In fact BTA’s often end up splitting therefore adding more anemones to your tank, whether you like it or not! 

Having two different types of anemones can be very risky but not impossible.  This should only really be attempted if you have a 5ft tank or larger though.  This is because anemones release nematocyst which can irritate the other anemones in the tank.  In a smaller tank it would be far more difficult for the tank to remove these nematocysts quickly enough resulting in possible death to your other tank inhabitants.  

Another thing to consider is that you run the risk of them bumping into each other and stinging each other.  The bigger the tank, the less chance there is of this happening.  As well as having a large tank, you could ensure that you add carbon into the tank either in an activated carbon bag or a reactor.  Regular water changes would also be beneficial as well as having spare RO water on hand in case of emergencies. 

I personally would not want the stress of keeping two different anemones together in one tank but as mentioned above, it is possible.  Some of the combinations I have seen are Rockflower anemones and Bubble Tip anemones, Sebae anemones and Bubble Tip anemones, Sebae and Mini Maxi Carpet anemones, Bubble Tip anemones and Rockflower anemones.  These are not the only combinations but what all reefers had in common was a large tank.  Large enough to keep the anemones far apart from each other.  

What clownfish will live in anemones

Clownfish are funny things.  They can call zoas, mushrooms, goniopora, torch coral and even green hair algae ‘home’, even when there is an anemone present in the tank.  It may take them years to decide to move into an anemone or maybe never at all. 

Providing Clownfish with an anemone doesn’t necessarily mean that they will be drawn to it.  Ocellaris and True Percula are the two clownfish that will naturally be drawn to an anemome such as Heteractis Magnifica but could take much longer, if at all, to be drawn to a Bubble Tip Anemone for example, because it’s not a natural host for them.

Carpet anemones have been known to host Clarkii, Percula, False Percula, Saddleback and other Clownfish.  However I would not recommend a Carpet anemone to beginners as they are notoriously hard to keep.  


Does an anemone need clownfish?

No, anemones don’t need clownfish to survive but they certainly benefit hosting them.  The most well-known benefit of clownfish is that they chase off predators such as Butterflyfish, Triggerfish and Batfish that like to pick at the tentacles of the anemones, and the fact clownfish ‘fertilize’ the anemone with their waste.    

A study done in 2013 by Nanette Chadwick concluded that clownfish helped provide the anemone they were hosting, with more oxygen and therefore more nutrients.  The clownfish constantly move thus opening up the space between the tentacles allowing more nutrients and oxygen to reach the anemone.  But that doesn’t mean that an anemone can’t survive without them.

Just remember that not all clownfish are hosted by all anemones and that some clownfish are particularly aggressive towards their host anemone so much so that they end up killing it.  Check out the most aggressive types of clownfish here.

Where do you put anemones?

In order to stop anemones from moving all over the aquarium and reducing the risk of them being sucked into powerheads and potentially killing everything in your tank, you can place anemones on their own rock which is set away from the main rockwork display.  Bubble Tip Anemones are notorious for this.  During their journeys around the tank they can end up stinging other coral. 

Most anemones don’t like moving over sand so this is a good way to keep them in one place.  However this isn’t foolproof.  Bubble Tip anemones frequently split and they can ‘waft’ around the tank until they find a place to call home. 

Sebae anemones live on the sand but need a rock to anchor themselves. 

So there you have it!

So, are anemones hard to keep?  Yes and no.  It all depends on what anemone you want (carpet anemones are notoriously hard to keep) and whether or not you want an anemone-only tank or to have it in a display tank with other coral and fish.  

A larger tank is better for anemones as apart from being more stable, they can wander about without hopefully bumping into too many coral. 

Some anemones eat fish whilst others move about regularly.   And having an anemone doesn’t necessarily mean that it will become host to your Clownfish. 

But, they are amazing to watch.  I like nothing better than to see an anemone’s tentacles waving in the flow.  Even better is if they are hosting Clownfish.  

All that’s left to say is, always do your research before purchasing an anemone.  Not after!  It’s much easier that way.  

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