As with all marine critters, you need to make sure you know what you’re getting yourself into before you get an anemone. What they truly need to thrive might surprise you. The below is based on my first hand experiences and some information & articles I found on Reefkeeping magazine (reefkeeping.com) and one article published by Greg Peterson and Marina Peters.

Water Quality
Generally speaking, they need the same type of water conditions as SPS require. Anemones need: high levels of dissolved O2, a stable salinity at 1.024 to 1.026, a stable PH between 8.1 and 8.3, a stable temp between 76 and 78 F, stable calcium between 400 and 450, stable dKH at 8.0 to 12.0, magnesium stable between 1,250 and 1,350 ppm, nitrate at 0.1 ppm or less (0 is best), stable phosphate at 0.1 ppm or less (0 is best), and finally 0ppm of ammonia and nitrite. Just as with most all aquatic life, stable parameters and parameters at or near the desired levels is the key to a healthy and happy tank.

In my experience, my parameters are always within those levels and remain stable. The only thing I’m not completely positive on what the ideal phosphate and nitrate levels should be for anemones (mine are typically always at zero). I have read a lot of differing opinions on that and have not been able to validate the tolerable levels for an anemone. Most say anemones can tolerate a very small amount but need 0 nitrate and phosphates in order for the anemone to truly thrive. But having said that, it’s always best to have your phosphate and nitrate levels as close to 0 as possible as it helps avoid other issues such as algae growth.

Tank Stability
This is even more important to people who are newer to the hobby as compared to seasoned veterans (and just to be clear, I’m not claiming to be a seasoned veteran here either). The reason being is that tanks that have been set up and running for less than 6 months can be prone to wide swings in water parameters. However, this is a generalized statement (rule of thumb) that can depend on a wide array of factors like total water volume and cycling methods just to name two of them. It is always better to play it safe and wait until you know for certain that your tank is stable, or wait 6 months (or even longer). Most anemones cannot handle swings in water parameters very well at all.

Maintaining stability will also influence such things as how you dose your tank (should you need to) and your maintenance routine. It is always preferable to ensure any changes in the water are made slowly and over a longer period of time

Water Flow
Anemones need at least some water flow around them. They breathe by absorbing oxygen directly from the water. In the wild, anemones also need water flow to bring food to them and for carrying away wastes. Generally speaking, anemones will need moderate to low water flow. One of the most common causes for an anemone not to be happy in your tank is that they do not like the water flow around them. This will sometimes cause them to move until they find a spot in the tank that they like.

It’s always best to match the flow in your tank to the type of anemone that you have. For example, bubble tips will be OK with flows that are higher as compared to what a carpet anemone would like.

Lighting Requirements
Anemones need really good lighting to survive. They will get a lot of their required nutrients through photosynthetic processes. They contain zooxanthellae algae within their tissues that will allow them to use light for nutrients. Their lighting requirements are very similar to that of SPS corals. Metal halides or T5 HO fixtures traditionally have been the best choices for light fixtures. I have not used, nor have I been able to find a good source of info on LEDs lighting and anemones so I really don’t know for certain if LEDs will provide a anemone with enough light.

There is a lot of differing opinions over what a minimum light requirement should be. I have found as a general rule of thumb, 4 watts per gallon of 18000K or higher lighting should be a good starting point for tanks that are about 20 to 24” in height. Once again, that is only based on the success that I have had with my anemones.

Feeding anemones
There are a few schools of thought on this as well. Some people do not feed their anemone anything and they remain healthy in their tank for many years. IMO, you should feed your anemone at least 3 or 4 times per month to keep them very healthy and happy. You can even feed them up to 4 times a week if you want to accelerate their growth. I feed mine about weekly and they grow and spawn and seem to be thriving.

As for foods, stick to meaty foods that are high in proteins. Claims, Scallops, Shrimp, and Krull are all good choices to offer. Stay away from silversides as much as possible. Typically you are risking potential quality issues with silversides as compared to the other above listed choices. There are other options for food, but I have not tried any of them.

When you feed your anemone, make sure the food is small enough to easily fit in the anemones mouth. Place the food near the anemones mouth (as near as you can). I use a long pair of tweezers for this. Once the food touches the anemone, it should start to react right away. Anemones can take up to 2 to 3 minutes to take the food and put it in its mouth followed by closing it’s mouth. A stressed anemone will take longer. Just keep an eye on the other critters and fish in the tank as they usually will try to steel food form the anemone.

Clownfish
Do anemones need clown fish ?.......... No they do not. Anemones are perfectly fine without them. There are certain benefits to having clown fish hosting in your anemone though. Benefits like: the clownfish will defend the anemone from all other fish and some critters in the tank, the clown fish will place uneaten food on the anemone (basically feeding it) and the clown fish will gain protection from other fish by hosting in the anemone. However, both the clown fish and anemone can be perfectly healthy and happy without each other.
If you are going to get a pair of clown fish to host in your anemone, make sure you get the correct type of clown fish that will naturally host in your anemone. As a general rule of thumb, not all clown fish will host in all anemones.

Other Tank-mates
For the most part reef tanks are pretty safe for anemones. There are not too many critters that will potentially harm your anemone. In the wild, some anemone predators include certain types of nudibranchs, bristle worms, butterfly fish, large angelfish, and large puffers. Even if a clownfish pair is present and hosting in the anemone, predators can nip at the anemone until the anemone eventually dies from the constant stress or injuries.

On the other hand, an anemone can represent a risk to other tank inhabitants. They are very opportunistic feeders grabbing and eating almost any smaller slow moving fish or invert that may come in contact with their tentacles. Although I have never personally seen this, I have found a lot of examples of anemones eating: gobies, dragonets, seahorses, snails, crabs, and blennies, Certain carpet anemones are more likely to snack your fish as compared to other anemones.

One of the best and natural ways to protect your anemone from potential predators and to help prevent other fish and inverts from becoming the anemone’s snack, is to keep a pair of clownfish in the tank that will host in your anemone. The clownfish will claim the anemone as their home and they will protect it. But please keep in mind that you do not need to have clown fish to keep your anemone happy. I would actually suggest waiting until your anemone is around ½ grown before getting clownfish. Clownfish can sometimes be rough on an anemone so you want to make sure the anemone is big enough to take all that lov’n.

Wandering Anemones

Anemones move because they are not happy with the spot they are currently sitting in. This could be for a great many reasons. Sometimes this can be an indication that something is wrong in the tank or the result of something that you might have changed. The things you would want to look into are
1) Water quality. You need to make sure all your water parameters are in line and that they are stable
2) Lighting. Make sure your lighting is bright enough and at the correct K value. If your bulbs are older than a year, consider changing them.
3) Water flow. This could be one of three things, a) there could be too little flow (but often it’s too much), b) there could be too much flow, and c) there could have been a resent change in the flow
4) Security. The anemone might be having trouble getting it’s boot (foot) in a spot where it feels safe. Sometimes that is because the substrate is not deep enough or there is no safe rock location

Once you have found what is causing the anemone to move, you can correct that to allow your anemone to settle into a spot he likes

Happy Anemones
Once you get to know your anemone, it should be easy to tell when it’s happy. Below are a few signs you can go by as well:
A) They are not hiding, remaining out in the open.
B) The color looks normal for that particular species of anemone. Quit often, they will also have a brown tint or undertone in the coloring from the zooxanthellae inside. Be cautious of died anemones. They will typically have been dyed a bright and attractive color. When dyed, the anemone will typically have a universal coloring throughout its body.
C) They should be fully inflated and look firm.
D) The mouth should stay closed.
E) The anemone should not be closed / retracted for long periods of time.
F) The anemone should have a strong feeding response. If you place a pc if food anywhere that comes in direct contact with the tentacles, the anemone should grab it right away and move the food into its mouth.
G) The foot should remain at least a little sticky, and the tentacles somewhat sticky as well. Some species of anemones will have stickier tentacles than others


Not Happy Anemones
The below are signs of a stressed or potentially sick anemone. Keep in mind you have to properly acclimate your anemone into your tank (both the water and the light), just as you would for sensitive fish with the addition of slowly acclimating the anemone to your lighting as well. Improper acclimation can cause many of the below symptoms and it could get worse. As anemones are very biologically simple creatures, they have a very tough time dealing stress. These signs can include:
A) The anemone is expelling a long and stringy brown liquid. This could be a sign the water conditions are not good and you anemone is expelling some of its zooxanthellae. This can be a serious condition. Just be sure the anemone is not expelling food wastes (keep in mind there is only one opening to the digestive system).
B) The anemone seams to shrink and expand a lot. Anemones will deflate and then re-inflate as a way of changing the water inside of them flushing out wastes. If this is continually happening (say daily or more), or if it remains shrunk for longer periods of time, your anemone might be having problems or is stressed
C) The mouth is open when it is not eating or expelling wasts
D) When an anemone moves into the rocks and hides from sight. (with the exception of rock anemones)
E) It won’t eat
F) Your anemone looks pale or almost colorless, otherwise known as “bleaching”. Basically this is another symptom / result of the anemone expelling zooxanthellae or was not properly acclimated to your tank lighting.
G) The mouth remains open or perhaps even extended although the anemone is not eating. In extreme cases of stress, the mouth will appear inverted.
H) The anemone will not attach its self