In-Depth Zoanthid Coral Care Guide for Beginners

Zoanthids are the perfect choice for beginners. Bright and vivid corals with a great growth rate and easy-to-keep attitude. This article is a detailed care guide for Zoanthids. Water quality, light, fragging, dealing with pests  — just to begin.

Basic Information

Are you keeping Zoanthids or planning to do so? Read on, as this is the only article you will need to keep these beautiful corals at your reef tank!

Natural habitat and appearance

Zoanthids live in tropical waters but some species may be found as far as the north-eastern Atlantic or Caribbean. They usually inhabit places where there is solid ground for colony spreading. For example, reefs, local coasts, or clam shells. The mid-water and subtropics are also home to zoanthids. Depending on the habitat, the appearance changes. Deeper individuals are elongated with long polyps, while coastal representatives grow in width to capture the largest area and spread over.

The color of zoanthids varies from species to species. From crystal white (white PE) to orange-red or purple (Red Hornet Zoanthids) and even black (Black Hornet)

Placement in a Reef Tank

Since Zoanthids live all over the ocean (from the depths to the coast), you can put them anywhere in the aquarium as well. The main prerequisite is careful observation. As long as you have isolated the coral and it went through an adaptation period, you can place it on a sandbed, settle it on rocks or in the corner of the tank. The only basic rule of thumb is to keep a distance of 3 inches from other residents to avoid the release of toxins.

Water Quality

Water is an absolute must when it comes down to reef keeping. High-quality water = more healthy corals and animals = less headache.

Calcium

The suggested setting that fits Zoanthid leather coral is from 380ppm to 420 ppm depending on other parameters. Take 380 and add little by little. About 5 ppm every 2-3 days will be great for your reef tank.

Alkalinity 

I recommend using about 425 to 450 ppm for Zoanthid corals. This is an average value that can be experimented with further. Depending on the corals and fish you already have, your aquarium may have different bicarbonate needs. 

Useful info: more than 75% of aquarists use 8 to 9 meq\L  Alkalinity (the equivalent of 400-450 ppm) Here is a conversion calculator.

pH (power of hydrogen)

Remember I told you about balance in the water? Well, pH is the essence of high-quality water. Zoanthid coral requires a pH of 8 to 8.3.

What if your pH is higher\lower? The next paragraph is for you then.

To raise pH  —  add baking soda. To lower it, consider adding vinegar or lemon juice, or “pH down” products.  Don’t rush when adjusting pH. The rule of thumb here is a step-by-step approach.

Useful tip: Schedule partial water changes (25%) monthly and plan smaller changes of 10-15% every week or fortnight to recover natural pH.

Temperature and Flow

Zoanthid Coral requires medium to high water flow and a temperature of about 80 degrees Fahrenheit. You can determine the right conditions by the appearance of the coral. If the body of the coral is elongated with long tentacles, then it was living in a deeper area where the water flow is average and the temperature is about 76-78 degrees Fahrenheit. Coastal corals are typically shorter, flatter in body, with polyps growing wide apart (80-82 degrees Fahrenheit and high tidal flow).

Lighting

Great light would be from 50 to 140 PAR. Zoanthid coral lives all over the ocean. From the deep sea to the very shelf. Their colonies are very adaptable to lightning but prefer low to moderate intensity (on average 90 PAR). With more than 100 species Zoanthids may benefit even from saturated 150+ PAR light. Here is a table with some popular species:

As for spectrum, I suggest 400-470nm. But avoid too much white spectrum(not more than 40%). I make 60% blue for 10 hours and 40% white for 6 hours. For another 8 hours, I put the lights on hold. The best thing for me was metal halides with T5 in second place, followed by LEDs.

Compatibility with Other Species

Here are some popular animal species:

Based on other aquarists’ experience.

Tip: clownfish sometimes like to host zoanthids. Here is a list of anemones and corals that are suitable for clownfish.

Conventionally, corals can be divided into 3 categories when it comes to compatibility.

Aggressors, defensive and passive. Here is the relationship among types:

Zoanthids are defensive corals. The protection mechanism boils down to the application of palytoxin  — the ultimate toxic substance. Zoanthid releases a toxin into the environment that inhibits competitive coral growth, damaging from a distance. Other animals are also not eager to come into contact with the poison, so they stay away. 

However, zoanthid colonies rarely attack each other (if 2 or more Zoanthid colonies are neighbors).

The Biggest Problem Related to Zoanthid Coral 

This coral will suffer from pests from time to time. Here are a few of the most popular:

(based on 12 people I surveyed)

• Zoanthid eating nudibranchs. It receives the most complaints, so the tips will focus on solving problems with this pest.
• Sea spiders
• Bugs, worms
• Box snails
• Zoa pox

Although pests are a natural phenomenon, they must be dealt with. There are 3 main ways of pest control among aquarists:

Physical 

Manual labor, which means you have to explore the coral for pests with your eyes and then remove them with tweezers, baster, etc. The pests are often similar in color to the coral (so they have a better chance of going undetected) so be careful. You may want to use a magnifying glass or zoom on your phone camera. Explore the zoanthid from every angle to spot the eggs. Zoanthid eating nudibranchs asexual, so if you find several of them in the aquarium, chances are good that they have already laid eggs in the most hidden corners. Usually, nudibranchs lay up to a hundred eggs, which hatch between 2 and 4 days. It is much easier to spot and eliminate the eggs before they become full-fledged pests.

Chemical

The chemical composition of dip products eliminates bacteria and acts like disinfectants. You will need 2 containers and some water from the aquarium. Shake the dip before use and mix with water according to package directions (usually 20-25 ml per gallon of water) NEVER apply dip directly into the tank, use a separate container. Put the diseased coral in a bowl and use a baster to allow the dip to penetrate all parts of the coral. Dip the polyps from the top, bottom, and sides. This procedure takes on average 5 to 15 minutes. Place coral in a container with tank water at the end of the procedure and rinse off the chemicals.

Do not use the dip more than 1 time per coral. Toxins can remain in the solution.

Natural

Depending on the population of your reef tank, you may find some fish and animals which will help you with bacterias and pests. Being a portion of food for some fish doesn’t make the pests’ life easier. The most common choice versus zoanthid eating nudibranchs is to populate a tank with wrasses. (Six-line wrasse and yellow wrasse in particular)  White-barred wrasse and Checkerboard wrasse also work well. The principle of this method is based on the hunting instincts of fish. To put it simply, they just need food to live. So they hunt the pests. The advantage of this approach is its flexibility and results. If you figure out which fish are suitable for you (to keep the balance in the tank and not to harm the corals), this method is the best.

Here is a quick comparison of the methods. I rated the Speed, Effort and Frequency from 1(minimum efficiency) to 5(maximum efficiency) 

Dealing with Zoa Pox

Another checklist to fight back the Zoa Pox

• Turn off the light (to force the closing of zoanthids for protection)
• Mix a pack of Furan-2 with tank water in a separate container
• Stir for 5 — 10 minutes (the solution is ready when there are no visible particles in the water)
• Put “infected” polyps (they have to be closed) into the solution
• Don’t make the treatment session longer than 30 minutes
• Repeat the procedure every 24 hours (in total 3 sessions in 3 days for a coral)
• Rinse the coral before placing it into the tank
• Wait a week after a session. If there is no visible healing, repeat the cycle (3 more dippings with 24 hours break)

Feeding Zoanthid Coral

There is no need for targeted feeding. Zoanthid coral lives in symbiosis with algae, which converts the energy of the sun into the food. Partial water changes, light, and good water flow are key factors affecting the ability to absorb the sun’s energy.

If you have a small aquarium, excess food will accumulate and contaminate the water. There are two possibilities here:

1. You won’t clean up the debris immediately and there will be favorable conditions for bacteria, algae and other microorganisms that reduce the pleasing appearance of your tank.
2. You will fight the contaminants. Perhaps with increased filtration, water flow or chemical additives. Suppose you start using activated carbon more actively. If you do, you risk upsetting the balance of elements in the aquarium and putting all its inhabitants under stress. Do you really want it? 

But if you want to feed your Zoanthids for whatever reason, be sure to use meaty food as brine shrimps, copepods, rotifers, krill, ancefis, etc. You can also consider amino acid supplements and pre-made food products (both online orders and local pet shops work well). Once you have the food:

• Mix it with tank water. Use a separate container to thin the food out
• Turn off the water circulation in the aquarium
• Apply the nutrient mixture to the polyps with a turkey baster

Feeding zoanthids is a spectacular process. As a polyp slowly takes food into its mouth, many hobbyists remember the Kraken from Pirates of the Caribbean.  

Don’t forget to install a protein skimmer and filtration system to eliminate the effects of contamination from feeding the corals with food containing protein and amino acids

Conclusion: The zoanthids living in small aquariums almost never need to be fed. Even in large aquariums, additional feeding often causes more headaches than benefits. I again suggest focusing on water quality and environmental factors such as light. You can read more about feeding corals here

How To Frag Zoanthid Coral

Zoanthid Coral requires extreme care when it comes to fragging (as it’s toxic).  I’ve prepared a step-by-step guide, so you don’t get hurt.

Before we start, make sure to take every single safety precaution seriously as palytoxin is no laughing matter. It can cause:

• Burning and tingling of the skin
• Altered or metallic taste 
• Hypertension
• Flu-like symptoms 
• Respiratory depression
• Coma or even death

Assuming that you understand how serious it is, let’s get started. 

Preparations (step 1)

Here is what you need to frag a zoanthid:

• Scalpel and tweezers 
• Coral glue and paper towel
• Frag plugs (or piece of rock from the aquarium)
• Latex gloves (glue and slime protection)
• Protective eyewear (Toxin in contact with the eyes can cause partial or complete eyesight loss)
• Three clean containers
• Coral dip and aquarium water
• At least 70 degrees Fahrenheit in the room

Get your safety equipment on and add the aquarium water to the containers you’ve prepared. You may want to number them as 1,2,3 for convenience. As each container is meant for something specific. 

Container #1 will be the place to hold zoanthid frag before cutting

Container #2 contains coral dip where you’ll place the coral after fragging

Container #3 is for the final rinse (before placing new frags into the aquarium)

Cutting (Step 2)

Use tweezers to grab the frag from the 1st container. Then Investigate the coral to decide what is the best place to take a cut. Zoanthids have fleshy polyps, so I advise you to put the specimen into the water (head over heels) and shake a little bit. This way polyps retract and it’ll be much easier to make a perfect cut.

Imagine that you need to separate a small piece from the head of cauliflower (it is much easier to tear off a whole floret together with the stem than to chaotically cut out several parts of different florets with a knife. First, the cauliflower begins to crumble, and second, it will no longer be attractive. Zoanthids have a similar structure. Visually find the detached part with the polyps and then plunge the scalpel at an arbitrary angle. Take your time, otherwise, you might damage the coral and make life difficult for yourself (more dealt damage = more toxic mucus secreted)

Gluing (Step 3)

Cut the piece to the base and hook the potential frag with tweezers. Then use a paper towel to make the coral dry.

• Take the glue and fragging plug (or you can use a piece of rock)
• Spread a small dab of glue on the plug
• Lay the specimen on a layer of glue (easier to do by tweezers or scalpel)
• Press down the specimen with a light squeeze of your finger
• place the plug into container #2 (fresh cut heal and curing of the glue)

Relocation into the Tank (Step 4)

Transfer healed corals to the rinsing container (#3) and let them sit there for 5 to 20 minutes. After that, you can safely move them into the aquarium. Make sure to provide adequate spacing for zoanthid frags (at least 3 inches)

Useful Tips

• Clean the tools. You don’t want your tools to be rusty. The best way to keep equipment clean is reverse osmosis (RO)
• The more polyps a coral has, the more fragments you can remove without risk. 6-10 heads would be a great start
• Never place the zoanthid directly into the tank after fragging. First place the coral in an enclosed container which is filled with the same water as the tank. By isolating it for 10-15 minutes you will avoid the release of dangerous toxins in the aquarium.
• Mild water flow and a slight decrease in lighting can help the coral to adapt faster
• Zoanthids spread and grow quickly, making them a great option for extra profit on par with green star polyp, toadstool leather coral, and mushroom coral. You can read more about how to grow coral for profit in this article
• In addition to regular glue, two-part epoxy can be used. The package is divided into two parts, which are firmly connected when they interact. To do this, just cut and knead the epoxy.

As you see, Zoanthid coral requires just a touch of attention. It’s not aggressive and adapts to almost any adequate conditions. Zoanthid will not cause any problems, which makes it a perfect fit for beginners (of course if you provide adequate water quality, minerals)