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Feeding Zoanthids

Have you ever wondered why my zoanthids are melting away? Why are there white bumps on my zoanthids? Why are my zoanthids losing their color? Why does it seem that there is always something wrong with one or the other zoanthid? And why aren't my zoanthids growing?

You hear a million explanations, you have to do a million things, and in the end, the problem just comes back. I'm telling you to stop wasting time and money on vague remedies and expensive additives.

Is it true that zoanthids can obtain the majority of their energy from light? Yes, that's true. But until we can give them PAR values of 600 – 1000 at 1 meter deep, this is simply not enough even for the brightest-lit aquarium. Our only hope is to supplement their energy with good nutrition. In this article, we will explore two types of food that zoanthids need, the results they provide, and how to mitigate the side effects associated with heavy feeding. We assume here that the water in your sea aquarium is stable and within accepted ranges (pH 8-8.4, Kh 9-11, Salinity 1.024-26, Magnesium 1000+).

Organic Energy

Organic energy, in this article, refers to all nutrients that have a living source. For zoanthids, this includes phyto- and zooplankton and oyster eggs. Microscopic life, as mentioned, contains the building materials for life: acids and proteins. Every living being on this planet has them and needs them. Zoanthids are no different. Since salt mixes contain nothing organic, and, as mentioned, zoanthids cannot live on light alone, we must dose these building materials into our aquarium to prevent stagnation and polyp death.

Let's discuss a few readily available products:

I recommend a dosage of 10 ml per 100 liters per day, more for very populated tanks. This product contains amino acids and fatty acids, as well as fibers and color-enhancing carotenoids. It works best in smaller aquariums but can also do wonders in large ones. You don't need to refrigerate it.

Identical to Chromaplex in nutrients, only with larger particles, which works well for Palythoa. The dosage is the same as Chromaplex.

Oyster Eggs
High in protein and omega-3 fatty acids. This feed is best used as an addition to other feeds. Use 2 ml per 100 liters in all aquariums, except when there is almost nothing in it. This product is expensive and should be kept in the refrigerator, making it uneconomical for larger aquariums.

This product mainly contains fatty acids. It's a hassle to keep this product good. You have to shake it every day to maintain its nutritional value. It must also be refrigerated. If you don't do this, it has no nutrition for your corals and is only good for your drain. If you still want to use it, use it only in larger aquariums because it contains too many unwanted substances that can quickly unbalance a nano reef.

Marine Snow
This product has not been on the market for long, but the results are good.
The price is a disadvantage, making it uneconomical for larger aquariums.

Which one to use? Pick one that best suits your aquarium and occupancy. And don't wait: your zoanthids are hungry!

nice coloured garden of zoanthus

Inorganic Energy

Inorganic energy refers to essential nutrients for zoanthids that do not come from organisms in your aquarium. I mean, of course, the chemical additives known as trace elements. There are a huge number of products on the market that contain these nutrients, too many to discuss individually. Fear not, the vast majority live up to their claims and indeed contain the correct trace elements. Below are some ingredients that should be in the product of your choice.

Manganese – Basic element for photosynthesis

Iron – Basic element for photosynthesis

Zinc – Basic element for photosynthesis

Fluoride – Prevents infections

Iodine – Add separately

Iodine should not be present in the product, as it breaks down the other products. But because it is essential for the vitality of the zoanthids, you must add this separately.


These can be divided into three main categories: Growth, Coloring, and Health.

Growth – As mentioned earlier, zoanthids obtain the majority of their energy from light. And because most aquariums cannot meet the demand for light, we need to supplement heavily. Growth visibly and explosively increases, transforming your aquarium into a sea of color in just a few months.

Coloring – Like most zoanthid enthusiasts, you may have noticed that colonies coming from the wild quickly lose their dazzling color. It's disappointing. But if you continue to feed well, this will no longer happen, provided you have bright light, of course. Eventually, the condition of your aquarium can be so good that you can care for discolored or sometimes unhealthy colonies and bring them back to their original bright colors.

Health – As with most living things, well-fed means healthy. And because we can't overfeed our zoanthids, obesity is not a problem. What do healthy polyps mean for you? Simple: no fungus or bacterial infections, no more dipping in freshwater, playing doctor, or ruining your favorite zoanthid.

Side Effects

If you've been paying attention, your next question should be: but what about the algae? It will happen, no ifs, ands, or buts. However, contrary to what is generally believed, in a well-maintained and balanced reef, algae are a temporary phenomenon, never the rule.

In a sea aquarium, a significant change in parameters over a longer period, or constantly changing parameters, such as in a new aquarium, leads to an algae outbreak. Whether you feed heavily or not. The most common mistake made by most aquarium keepers is to stop feeding as soon as algae appear. Don't do it!
Continue feeding and let your aquarium balance itself over a period of 2 – 4 months. First, you'll see cyano, then brown slime and diatoms, and eventually hair algae. This is normal. When your algae cycle is complete, you will see that the algae make way for calcareous algae.

If you absolutely can't stand the algae, you can add some algae eaters like hermit crabs, snails, and algae-eating crabs. This reduces your cycle by a few weeks. By reducing your light period and temperature, you shorten it by another 2 weeks. Then slowly, very slowly, you can bring it back to the desired levels.

What are you waiting for? Feed and enjoy tremendous growth and color.