Introduction to Acan Care
Acanthastrea (Acans) is one of the more desirable corals in the reef aquarium hobby. Acans are known for being leading centerpieces in many marine displays because of their colorful and unique appearances and relatively forgiving nature. From the mighty Iron Man Acan, famous for its neon colors to the mesmerizing Skittles Acan, this ultimate guide to Acan care will take you through everything you need to know to keep these corals thriving.
What Are Acans?
Acan corals are part of the Lobophylliidae family and are widely distributed in the Indo-Pacific, particularly in the waters surrounding Australia, Indonesia, and the Red Sea. Their natural habitat is typically up to 50m deep with moderate water movement and light intensity.
Acans have a stunning array of colors which is a huge draw to hobbyists, and why they are one of the most popular large polyp stony (LPS) corals. These corals exhibit some of the most vibrant color combinations in the reef realm — from electric greens and blinding purples to startling reds and deep oranges. Their unique skeletal structure produces colonies of round polyps with visible corallite walls, making them appear to have many "mouths" on a single colony.
Water Parameters For Acan Corals
Proper water parameters are key for Acan health. Although Acan corals are slightly more forgiving than some other LPS corals, Acans still need consistent reef conditions. These include:
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Temperature: 72-78°F (22-26°C)
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Salinity: 1.023-1.025
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Alkalinity: 8-12 dKH
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Calcium: 400-480 ppm
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Magnesium: 1300-1400 ppm
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pH: 8.1-8.4
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Nitrate: 0-5 ppm (Acans can handle a slightly higher number than other LPS corals)
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Phosphate: 0.01-0.05 ppm
When maintaining water parameters, parameter stability goes further than focusing on getting “perfect” numbers. Even though Acan corals are typically more hardy than SPS corals, sudden changes can still cause stress. You should aim for accurate testing kits and frequent maintenance so that you can fine-tune the water parameters when needed.
Acan Coral Lighting In Reef Aquariums
Acan corals can adapt to various lighting conditions, however, they thrive best in reef aquariums with low to moderate lighting intensity. We suggest the following lighting conditions for Acans:
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PAR Range: 50-100μmol/m²/s
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Light Spectrum: All spectrums with a focus on blue band for fluorescence
Some Acan corals can tolerate higher PAR levels, however, before increasing the light intensity inside your aquarium, always check the lighting requirements for your particular Acan species. Also, if you add a new Acan to your aquarium, it should be placed in low light, and slowly acclimated to their final position over a couple of weeks.
Most Acans thrive with moderate to strong blue LED lighting, which brings out their natural fluorescence while providing energy for photosynthesis.
Signs Of Poor Lighting In Aquarium
If your aquarium lighting is not quite right, your Acan coral may show you some signs as a cry for help.
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Excess light: Coral polyp retraction at peak intensities, bleaching (especially upper surfaces), or dull coloration.
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Insufficient lighting: Elongated polyps that are always "stretching" towards the top of the water column, slow growth, and loss of color.
Water Flow Requirements For Acan Corals
Acans love moderate, indirect water flow. You should aim for the water flow to be strong enough to keep debris from collecting but gentle enough that their polyps can fully extend.
If the water flow is too low, it allows detritus to settle onto coral tissues, which could cause necrosis. Yet, if the water flow is too strong, it prevents full polyp extension and can inhibit feeding.
We also suggest a directed flow with an oscillating current rather than a constant directional flow. Water pumps that have random flow patterns work best. We recommend the following pumps for reef aquariums:
Acan Coral Placement
Coral placement is a huge factor for Acan success. Acan corals should be placed in the mid-level of your rock work or raised slightly in the sand bed. You also want to place them around 8-14 inches from lighting fixtures.
Acan corals can be aggressive - their long sweeper tentacles (which can extend 2-3 inches!) can sting neighboring corals if Acans are defending their territory, damaging corals and in some cases, not giving up until the other coral is dead. To reduce aggression and coral warfare, you should ensure that Acan corals are at least 2-4 inches from other corals.
Feeding Acan Corals
Although Acans rely on symbiotic zooxanthellae (photosynthetic algae) for nourishment in the ocean, in an aquarium, we suggest periodic supplemental feeding to enhance your Acan’s growth rate and enhance coral coloration.
Feeding Acan corals is super fun and interesting. They are fairly aggressive feeders, so we recommend target feeding using a pipette or turkey baster. Acans love mysis shrimp, coral-specific pellets, amino acid supplements, and finely diced seafood approximately 2 to 3 times a week. At Reefco Aquariums we also make the following supplements in-house that will greatly benefit your Acan and other coral’s health:
Propagating Acan Corals
Acan keeping can be one of the most rewarding coral husbandries due to the relatively simple propagation methods. These corals can also be fragmented using standard coral-cutting techniques. For more information on fragging corals, read our article “A Complete Guide To Fragging Corals”.
Troubleshooting Acan Coral Issues
Even when we provide corals with the best care, sometimes issues happen. Below are the most common problems with Acan corals and what you can do to resolve the issue.
Tissue Recession
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Cause: Lack of feeding, overexposure to chemicals, or an aggressive neighbor
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Resolution: Feed more frequently and look for potential irritants
Loss Of Color
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Cause: Lighting or nutritional deficiencies
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Resolution: Understand PAR levels for corals, improve your feeding regime, and consider coral supplements
Coral Polyps Not Expanding
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Cause: Usually due to poor water quality or not enough flow
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Resolution: Set different flow patterns and test water parameters frequently
Brown Jelly Infection - A contagious, and potentially fatal tissue infection that turns coral brown and requires immediate intervention
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Cause: Bacterial infections, physical damage to tissues, and environmental stress from poor water maintenance
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Resolution: Physical removal of the brown jelly disease, antibiotic treatment, and improving tank conditions
Summary
Acan corals have interesting colorations, individual patterns, and a slightly forgiving nature which makes them perfect for both beginner and experienced hobbyists. When provided with stable water conditions, sufficient lighting, and water flow, along with a stable feeding regime, you will be rewarded with a vibrant and healthy coral that can be the focus point of your reef aquarium for years to come.
Whether it is your first Acan fragment or you are looking to increase a particular species already in your collection, contact the Reefco Aquariums team today to find out what Acan corals we have online and in-store.
