Adding anemones to your marine tank

Taking the mayhem out of marine fish keeping


Adding anemones to your marine tank

Anemones are often considered one of the harder marine invertebrates to keep long term in the home marine aquarium. It is thought that these animals don’t actually age in the wild so can theoretically reach very old age but often meet their end through biological factors such as predation.


It is unfortunate then that many of these magnificent animals die in short time periods at the hands of inexperienced marine hobbyists when so much can actually be done to prevent these tragedies.


Anemones require good, strong lighting, suitable flow rates ad direction and good water parameters. Above all they demand stability within the marine tank. You may often read that anemones shouldn’t be introduced to a newly set up marine tank until that set up is at least a year old. This rough guide is assuming that within a year the aquarium will have been through all the settling down changes in parameters and the hobbyist has gone through the steep learning curve of keeping things stable and developing a suitable maintenance routine.

So, the time has come, you are satisfied that your tank can accommodate and maintain a healthy anemone, water parameters are good and stable with a low nutrient (Nitrate and Phosphate) level. One thing I have learned over the years is that many anemones seem to be very intolerant to any detectable levels of Phosphate. You can finally introduce an anemone into your tank with the hope that your pair of clown fish are going to dive in there and live happily ever after. For a more detailed look at which anemones to choose and paring them with clown fish look here.


For the purposes of this page I’m just going to focus on the most appropriate way of introducing an anemone to your marine aquarium.


At the shop


As with all livestock, chose a healthy looking specimen. You are looking for something that instinctively looks happy, good colour, well inflated and with its single foot well attached to something. Avoid something that resembles a half inflated balloon, pale, white or translucent in clolour, floating about in the flow. A healthy anemone should always have its foot attached securely to something.


Tears in the anemones flesh can be fatal, check there are no tears in the foot or the central mouth disk, you also need to remember this when you chose your anemone. You have chosen your specimen partly because its foot is solidly anchored within a crevice in a piece of rock which indicates it’s healthy. Therein lies a problem, it can be almost impossible to remove the foot safely from the rock without tearing it which may result in a dead anemone two weeks down the line. A decent shop will offer to sell the rock to you as well and you should be prepared to do this. Other tricks are to rub its foot gently with an ice cube which can make it release or reposition the rock in some strong flow and hope the anemone will jump ship to find a more suitable and desirable residence. If the shop assistant continues to brutally try and force the delicate foot off the rock your best bet is to walk away empty handed.


At home


So you have chosen your healthy looking specimen and have taken it home with its foot intact and as quickly as you could so now is the time for acclimatising. This method is the same as that for snails and other sensitive invertebrates (see here). You should carry this out over a prolonged period to reduce the stress on this most sensitive of creatures.

Placing your anemone in the tank


Some people recommend turning the power heads off when you do this so your anemone doesn’t get blown off your chosen spot by the flow. One issue with this is that anemones are very picky about both the intensity and direction of flow and this pickiness is right down to individual preference rather than species so you have no way of judging just which is the perfect spot for it. You may get it to settle nicely whilst there is no flow only to find that it goes walkies as soon as you have turned your powerheads back on.


My preferred method is to actually leave the powerheads on, gently remove the anemone from the bag (underwater) and hold it gently in the spot I have identified for it. If you are patient and wait long enough you should feel it starting to put its foot down. When you’re happy it is at least partially secured, remove your hand from the tank, stand back and start the 48 hours of panic you will inevitably experience whilst you wait to see if it unhitches and starts travelling (or worse floating) around your aquarium.


There is a highly recommended precaution you should consider when introducing an anemone to your tank which is to cover all powerheads and intakes with something (filter socks, tights, filter floss) to make them anemone proof. Should an anemone get drawn into a powerhead or filter intake not only will it almost always result in the demise of your animal but has the potential to cause a complete tank wipe out. One of my anemones almost became soup after going wandering having stayed in the same place for years. Needless to say my boss was not impressed when I rolled into work two hours late explaining I couldn’t leave the house until I have cut my anemone out of a filter intake then had to make a nursery for the animal and rebuild my filter.


If your anemone does start wandering and you have to leave your tank unattended it may well be wise to turn the powerheads off for a while to allow it to settle. If it starts looking agitated you are probably better off leaving your hand out of the tank and letting it do its thing. Don’t be surprised if it settles right out of sight or even hides completely for a few days. Leave it alone, it has a lot to get used to and will come out and find its place when its ready. Don’t forget though that a wandering anemone can cause all sorts of issues if it wanders by your prized sps corals and starts stinging them.




Helpful tips




If you can always try and buy a tank split specimen. It’s quite common for these animals to divide in the home aquarium and both heal well so you end up with two identical creatures. These tank split animals are often considered hardier and easier to care for than wild collected animals.



Always be prepared to cover your powerheads and filter intakes




Anemones - in a nutshell

Anemones need strong light and good, stable water parameters




Always buy a healthy specimen, check for tears or damage, particularly on the delicate foot




Remember they can and will walk about so make sure the powerheads and filter intakes are well protected




Don’t rush the acclimatisation process as this will lead to an untimely death for your anemone




Remember anemones sting, that’s how they catch their food. If they start walking about the tank they can cause all sorts of damage




Some species of anemone such as carpet anemones can catch and eat fish from your aquarium. I had a large, green carpet anemone that grabbed my half grown tasselled filefish and promptly ate it infront of me with little I could do.




Anemones really don’t like Phosphate