Zoanthids Coral Care Guide – Understanding Zoas

Zoanthids Coral Care Guide

Zoanthid Corals are some of the most popular corals for both new and experienced aquarium keepers. Their beautiful colors are the main attraction, but the ease of care is also a huge attraction. Also referred to as Zoos, Zoas, or button polyps, these corals come in a variety of different colors and make a beautiful addition to any tank. But what exactly does it take to care for these corals? Today we will teach you everything you need to know about caring for Zoanthids including feeding instructions, lighting necessities, water flow guides, tank requirements, social behaviors, and more. Let’s not waste another minute!

A little about Zoanthid Corals

Did you know that there are over 100 different varieties of Zoanthid corals? In fish stores, however, there are three common zoanthids that you will run into. zoanthus, playthoa, and protopalythoa. The main distinction between these zoa is the degree to which the individual polyps are attached to one another.

The main draw of zoanthids is their unique and attractive colors. Zoanthids come in varieties of browns, grays, orange, red, yellow, green, blue, and any combination of colors. Many of these species are also neon and can give your tank the feel of an “alien-like” environment.

Zoanthids typically resemble tiny sea anemones. With that being said, unlike anemones, most zoanthids are found in colonies as opposed to individually.  Many people also consider them to resemble flowers.

In the wild, Zoanthids are found in a variety of marine environments around the world but are most commonly found in coral reefs and in the deep seas.

Feeding your Zoanthid Corals:

Zoanthids love to eat, and a well-fed Zoanthid is a happy Zoanthid. Feeding your Zoanthid regularly can help to promote growth and health. In your aquarium, Zoanthids can eat specially engineered coral reef food, brine shrimp, plankton, krill, and copepods, lancefish, bloodworms, and rotifers. I recommend Reef Roids. I have used this product for years with great results.

Most of these species are capable of capturing their own prey, so target feeding is not usually required. With that being said, should you choose to target feed your corals, just place the food as close to the center of the polyp as possible. From this point, the polyps will fold inward and the mouth will open for the food to enter. You can use a target feeder to make it easier and more accurate to feed them.

It’s important to understand that in addition to food, zoanthids also contain photosynthetic algae within their cells, which allows them to abstract energy from the sun.

Note: if you want your Zoanthids to grow quickly, a good combination of sunlight and regular feeding is essential.

Lighting for your Zoanthid Corals:

Zoanthids are relatively forgiving when it comes to their lighting conditions and can thrive in a variety of different lighting environments whether it be dark or light. Having said that, most Zoanthids prefer high lighting environments. The more light that your Zoanthid has, the faster the polyps will grow, the larger the polyps will grow, and the brighter their colors will be.

If you really want to make your aquarium pop, some popular types of zoas will have astonishing coloring when placed under actinic lights. Species that pop-under this type of lighting include fruit loops, fire and ice, whamming watermelon, and orange bam bam.

Reef quality LED, T5, Halides, or any combination will be sufficient for zoanthids. My zoanthids are currently growing under a pair of Kessil A160 Tuna Blues.

Flags of Red People Eaters Zoanthids under actinic lighting. 

Image Credit – Aaron Gustafson – Creative Commons Licence

Water flow for your Zoanthid Corals:

Zoanthid Corals require low to medium water flow. Too little water flow can make it difficult for them to feed, but too much can make it difficult for their polyps to open. If you aren’t sure whether or not your Zoanthid is happy with its placement in the flow of water, watch their behavior. If they open up and fully extend, they are happy. If they don’t, you might need to try a lighter or stronger water flow. Find a happy medium and zoanthids will thrive.

Zoanthid Coral Placement:

Zoanthids should be placed closer to the top or center of the aquarium where they can receive ample lighting. If you have strong lighting on your tank, they will do fine in the lower levels. As mentioned above, they should also be placed in an area where there is a mid-strength water flow. With that being said, this is a very broad generalization. Each Zoanthid is unique in its needs, and you can use their coloring as an indication as to how much lighting they actually need. The more intense and florescent the color of your Zoanthid, the more lighting it has previously had, and the more lighting it will need. The duller the Zoanthid, the less lighting it has previously had, and the less lighting it will need.

The best method of placing a Zoanthid is to take note of where it was most recently placed. Also note the previous tanks lighting, water parameters, and water flow rate. If it came from a previous tank, try to recreate the same positioning and environment in yours.

Tank Requirements for your Zoanthid Coral:

Zoanthids are much like other corals when it comes to their tank requirements. Aim for temperatures of 78 degrees F, with salinity around 1.025. pH should be between 8 and 8.4.

The truth is that Zoanthid Corals are pretty forgiving in their tank environment. With that being said, the key to keeping this type of coral alive and well is stability. A small drop in temperature overnight can quickly result in shriveling tentacles and fading colors. If you want your Zoanthid to survive, stable temperatures are essential.

You should also do regular checks of your salinity, alkalinity, magnesium, and calcium levels to ensure that they are all stable as well. I mention tank stability in many other articles. As with many corals, the more stable your tank is over a period of time, the healthier your zoanthids will be.

Zoanthid Coral Growth Rate:

The growth rate of Zoanthid corals is highly dependent on the variety of the coral you have. Some corals grow quickly, while others grow slower. With that being said, the environment also makes a huge difference in terms of how quickly a Zoanthid will grow. If a Zoanthid is happy with its placement in the tank and the water parameters, it will grow quicker. If it is unhappy with its placement, it will grow more slowly.

Note: Feeding can also promote the growth of Zoanthids. The more a Zoanthid eats, the quicker it is to grow.

Watermelon zoanthids

Image Credit – Eric Danley – Creative Commons

Zoanthid Compatibility:

Zoanthids are considered to be a defensive coral. This means that they are not aggressive and have a difficult time defending themselves. For this reason, Zoanthids can frequently become victim to stings from other corals. This can cause them to become damaged, or can even cause them to start losing heads. Aside from needing protection from other corals, this coral also needs protection from fish that like to nip on it. Zoanthids are covered in a protective slime coating that is considered to be a favorite among coral nipping fish. Once this slime coating has been nipped off, however, the coral will die.

Zoanthids are compatible with each other. Don’t worry about having different types of zoanthids together, they will do fine and the color combinations make a stunning colony.

A word on Zoa Pox:

Did you know that Zoanthid Corals have their own form of chickenpox? It’s called “zoa pox”.  This disease is very prevalent among Zoa corals and is characterized by tiny growths, usually in the form of white or yellow marks, on the side of the zoa. While these marks are evident on the outside of the Zoanthid corals, they also have a tendency to spread deep inside the stocks. When this happens, the polyps close up.

Unfortunately, the exact cause of Zoa pox is unknown. Some believe it could be related to a breach in the feeding schedule, others think it could be a voltage problem, but most think it’s a change in temperature that causes stress and leads to disease. The bottom line is, however, if you see that your Zoanthid has Zoa Pox, you have a sick coral on your hands.

How do you deal with a sick Zoanthid?

As mentioned in my article, Saltwater quarantine tanks, you should always have a QT set up and ready for livestock in the event of illness. Move your zoanthids into the hospital tank for treatment.

The first step to dealing with a sick Zoanthid is to turn off the tank lights for a while and wait for the Zoanthid to close before treatment. Once the Zoanthid is closed, add medication if needed, possibly Furan, following the mixing instructions, to a disposable container. Once the medication has dissolved, soak your Zoanthids in the medication for 30 minutes. Repeat this process once a day for three days. Reassess the situation in 4-7 days and repeat if needed.

It’s important not to move the coral back to your display tank until it is fully treated to prevent others from getting infected.

A note on toxicity:

While not true for all Zoanthids, many varieties of this species produce a toxic chemical known as palytoxin. If this toxin gets into a cut, into your eyes, or into your nose or mouth, it can slow your blood flow and cause neurological damage. It’s a very serious concern when dealing with zoanthids. Handling or fragging them should be done with caution. In most cases, this will not be life-threatening, but it’s always better to be safe than sorry. In return, any time you are handling zoanthids, be sure to use proper safety equipment and always handle with extreme care. If you are handling a Zoanthid, always wear protective gloves and goggles. Wash hands thoroughly with soap and water once you are finished.

Read more on fragging zoanthids and other corals here.

Overall zoanthids are a great coral for beginners and advanced hobbyists. They are a pretty forgiving coral and provided you give them the proper environment, they should thrive in your tank. There are a variety of types readily available for purchase online or at your local saltwater fish and coral store. They range drastically in price anywhere from $5 PP ( per polyp) up to $100PP and some colonies can cost thousands of dollars. But for the normal and non-rare types, expect to pay around $5-$10 PP. If you decide to add zoanthids to your reef tank, you won’t be disappointed.

Thanks for reading!

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