Did you know, in the wild, around 99% of Acropora (Acro) corals die within the first year? You may be wondering why? Simply, because the conditions in the wild are challenging, therefore, corals have to learn to adapt, and with increases in climate change, declining water quality, overfishing, pollution, and increasing coastal development, the ocean is a fairly difficult place to live.
Acropora corals are part of the SPS (small polyp stony) group of corals, which are slightly more demanding to care for than other corals. However, there are still some easy Acropora corals great for beginner reefers too, and with the right conditions, Acros thrive in any reef tank!
Just like LPS (large stony polyp) corals, it is important to consider the nutritional needs for SPS corals like your Acro. So, let’s dive straight in and take a look at why you should be feeding your Acropora and how to do so!
Do Acropora Corals Need Feeding?
With Acropora coral care, feeding is one of the requirements when keeping corals in a reef tank.
While it is true that your Acropora coral can get most of its nutritional requirements directly from the symbiotic algae that live within their tissues, called zooxanthellae, many Acropora corals can also catch prey in the water.
Lighting provides corals with approximately 85% of their nutrition, but feeding via broadcast and target feeding gives corals extra nutrition to boost their growth and coloration.
Where Do Acropora Corals Get Their Nutritional Requirements From?
Amino acids are simple organic compounds that contain an amino acid group (NH2) and a carboxyl (COOH) group. You probably remember back from high school that every biology book and biology teacher would repeat that “amino acids are components of proteins that are the building blocks of every cell”.
Amino acids are also important for neurotransmitter transport and biosynthesis, where simple structures are converted into complex structures. The amino acids your Acro requires depend on the species you have, and even if your Acro doesn’t use the amino acids, they will be utilized by another organism in your reef tank.
There are many commercially available amino acids you can buy online or at your local fish store (LFS). In terms of dosing, this is typically on the packaging, but if you are still unsure, speak to your LFS or where you bought them from.
For Acropora corals, rotifers and cyclops plankton are recommended. As Acros have small polyps, you should aim for food between 0.5 and 2 mm in size.
Many hobbyists will agree that reef tanks with a higher volume of fish will have a positive effect on Acropora colonies. This is because fish produce nitrogen, which corals need to survive.
How To Feed Acropora Corals: Target Feeding
While broadcast feeding is still a popular method when feeding Acropora corals, target feeding is a much easier, and more precise method, therefore the waste is much less!
By directly feeding Acros, you are providing them with the vital nutrients needed for optimum health that they will not get from when the zooxanthellae undergo photosynthesis (from the lighting in your aquarium).
Your Acropora coral craves essential nutrients such as nitrogen, phosphorus, amino acids, and trace elements (vitamins and minerals), which are found in coral foods. Apart from improving your coral’s overall health and boosting its nutrient storage, by feeding your Acro with these essential nutrients, you will see increases in your coral’s calcification rate. This has been scientifically proven, therefore, feeding will help your Acropora grow fast and promote healthy tissue growth!
Target Feeding Instructions:
- Prepare the amount of coral food required for one feeding, and put it into a cup that you can dip the pipette or turkey baster in.
- Turn off any pumps and skimmers, and wait until the water flow has died down inside the aquarium.
- With the cup of prepared coral food, fill your pipette or baster.
- Gently hovering over your Acropora corals, slowly release a small amount of coral food above each polyp, allowing them to catch the food. Do not blast them with food – you wouldn’t want food thrown in your face when you are trying to eat, well, nor do your Acropora Corals.
- It can be very easy to get carried away when target feeding that we often forget about the time. Set a timer, so you don’t forget to turn the pumps and skimmers on after 30 minutes.
If you have made up too much coral food, place it in a bottle and put it in the fridge to avoid wasting it.
When Should You Feed Acropora Corals?
Most Acros will enter “feeding mode” during the night or dark cycle in your reef tank. During this time, your Acropora’s axial corallite polyps usually fully extend because they contain very little, if any zooxanthellae, making them perfect for capturing food.
Saying that, some Acros like Acropora millepora, and the Homewrecker and Walt Disney Acro (A. tenius species), tend to extend their polyps during the day, rather than at night. The reason behind the difference is still unknown, however, it could be that Acropora corals have adapted to being aquacultured over the years in captivity.
Coral Food For Acropora Corals
There are many pre-made coral foods readily available at your LFS or online that your Acropora coral will accept. These include:
When you feed your Acro pre-made coral foods from LFS, unless you work in the manufacturers’ laboratory, you will not know exactly what is put inside the foods or the nutritional profile. Therefore, some reef hobbyists prefer to prepare their own food by defrosting frozen brine and mysis shrimp and mixing with some aquarium water.
When feeding any corals, remember to never overfeed your coral tank, as this can lead to your Acropora turning brown from elevated nutrient levels or algal blooms, which are a nuisance to remove! To avoid these headaches, only feed your Acropora coral 2-3 times per week and perform regular water changes and siphon out uneaten food.
While Acropora corals get most of their nutrition from lighting thanks to the zooxanthellae that live inside their tissues, feeding Acropora corals is recommended for them to thrive. This is easily achieved with pre-made coral food from LFS or preparing mysis or brine shrimp
By feeding your Acropora coral, your coral will thank you with faster growth and brighter coloration. For more information on how to feed your coral, check out our Acropora coral care guide.