Sick anemone

Sick anemone? How To Treat Them


Have you ever had problems with the anemones in your tanks becoming sickly? It’s important to monitor the health of all tank inhabitants, so if yours aren’t looking well, you will need to take action.

Treatment may vary slightly according to the kind of anemone you have and what is wrong with it, but most people treat their anemones with a broad spectrum antibiotic (usually Ciprofloxacin) that will kill a whole range of bacterial infections. If you take swift action, this could save your anemone.

Let’s find out a bit more about how to treat a sick anemone and what you can do to restore yours to full health as soon as possible. Don’t underestimate the importance of speedy action when one of your anemones is sick.

How Do You Treat A Sick Anemone?

To treat a sick anemone, you may wish to set up a hospital tank. This will prevent the infection from spreading to other anemones and often makes it easier to treat the anemone that has been infected. To set up your hospital tank, you are going to need:

  • A small plastic basket
  • Full spectrum lighting
  • A 50 watt heater
  • a 10-gallon tank (this is the hospital tank)
  • 250 mg Ciprofloxacin tablets (these are the antibiotics of choice, but you can use another if necessary)

To create your anemone’s hospital tank, you should:

  1. Get it set up with the correct temperature and salinity levels for your anemone. You may want to use water from your main system to minimize stress and ensure the conditions are suitable.
  2. Transfer the sick anemone into the plastic basket in the tank
  3. Dissolve the antibiotic tablet by wetting it and rubbing it between your fingers, and then wash it gently over the anemone, using the edge of the basket to break up the flow and prevent it from being too harsh.
  4. Turn the lights on and leave them on.
  5. The following day, change the water in the tank and repeat the process, applying the next dose of Ciprofloxacin. Keep the lights bright and avoid feeding the anemone while you are treating it.
  6. Keep cycling the water daily or more frequently if necessary so that there is no risk of the ammonia levels creeping up.

You will need to observe your anemone over the next 3 days to see if the antibiotics are working, and it is recovering. You should see the deflation that is usually associated with illness stop, and the mouth become tight. If this doesn’t happen, increase the dose of the antibiotic to a 500 mg Ciprofloxacin tablet and continue treatment.

If the deflation has stopped, continue treating with the same dose of antibiotic for at least 3 more days. This ensures that the bacteria have actually been killed. If you stop treating the anemone too early, there is a risk of the bacteria returning and developing a resistance to the antibiotic.

Can Anemones Recover?

You might think that your anemone is too far gone to be saved, but surprisingly, anemones can recover from all sorts of attacks and bacterial infections, and even a very sickly anemone can recover if you deal with the problem and then take good care of it while it rebuilds its strength and resources.

It can be difficult to know when an anemone is doomed, but it’s always worth trying to save one. If it still has a good grip on the rock, it’s quite likely that you can save it. You will need to treat the issue and then feed your anemone up and provide it with the best possible conditions if you are going to restore it to health.

Many people have found that anemones are capable of restoring themselves to full health despite a serious setback, and even some anemones that look dead can make a full recovery if their conditions are altered to make them more suitable.

However, be aware that it may take anemones a lot of time to recover if they are in a very bad way. You will need to work hard to ensure everything is as perfect as it can be, and feed the anemone regularly so that it has the strength to recover and regrow.

How Do I Know If My Anemone Is Dying?

The easiest way to tell if your anemone is dying is to look at its mouth. A sick anemone will start to invert its mouth, spilling its guts outward. You will find that it doesn’t close its mouth, and this is a good sign that something is seriously wrong.

You might also see that the tentacles deflate and stay deflated (temporary deflation is normal) for a long period. A few days is nothing to worry about, but if the tentacles remain flat after about three or four days have passed, you should be concerned.

If your anemone is really sick, it may lose its grip on the rock and become detached, falling to the floor of the tank. However, some anemones can retain some grip on the rock even after death, so don’t use this as your sole guide for your anemone’s health.

Another sign of sickness in an anemone is that it will shrink, becoming notably smaller than it was when it was healthy. Pieces of tissue may detach and drift away into the water, and this indicates that the animal is very sick and unlikely to recover – although it is still worth trying.

Finally, some sick anemones will lose their color and become pale shadows of their former selves. If your anemone is looking pale, check whether it is sick and take swift action to resolve the issue.


An anemone that is sick can often be saved by using a broad spectrum antibiotic, although there is no guarantee that this will work. You should consider moving it to a hospital tank during treatment, and remember to keep up the treatment for a few days even once it is starting to recover.

Always be vigilant for signs that an anemone is getting sick and act quickly if you see them.