Acan corals are found in the south Pacific, particularly around the Philippines, Papua New Guinea, and Australia in waters down to 30m.

Acanthastrea Corals, commonly known as Acan coral or Acan Lords, are Large Polip Stony (LPC) Corals and one of the most Beautifully Colored Coral species.

They come in purple, red, green, blue, orange, brown, rust, pale tan, and pale grey.

The family includes many species with different names.

Because one the most popular Acans was recently placed into a different genus, the common name now actually spans two genera: Acanthastrea and Micromussa.

The species in question is now named Micromussa Lordhowensis, also known as the Acan Lord.

Mircromussa Lordhowensis takes its name from Lord Howe Island.

This is one of the most coveted and expensive Acans.

Acan Corals are Large Polyp Stony Corals. A colony can have anywhere between one and several dozen Polyps.

The individual Polyps of Acans are noticeably larger than similar Corals, like the Micromussa species.

The Polyps form inside their individual Corallites which, together, form the colony skeleton. Unlike the Euphyllia species, the skeleton does not form a wall or branching structure, but more of  a flat, broad, stone-shaped skeleton.

Acans have a row of short feeding tentacles that line the perimeter of their mouths, inside each Polyp.

These tentacles are often visually present, and extended to some degree throughout the day. During feeding and at night, these tentacles extend further.

Acans also have sweeper tentacles and can be relatively aggressive.

Most reef keepers recommend keeping Acan colonies at least six inches from any other Coral, including other Acans. This distance is usually sufficient to prevent Corals from stinging each other in territorial disputes.

Acans grow by producing new heads and they will eventually form a dome shape when fully grown.

In some cases, they are known to grow rapidly that they sprout a new head every 7-14 days once feeding needs are met and optimal water parameters are maintained.

Placement of your Acan Corals can greatly affect its growth potentials.   

They can be placed on the tank bottom, sand bed, or on Live Rock, the placement position can either enhance or inhibit how the Colony will grow out.

It has been duly observed that keeping an Acan on the tank bottom gives it a ball shape, but this significantly limits its growth rate.

Furthermore, placing the Acan Corals on the sand bed can be detrimental, because, in the advent of high water movements, sand can get trapped in between the skeleton and tissue leading to their demise.

On the other hand, if the Coral is fastened to a Live Rock, it will grow out uniformly in accordance to the shape. The Coral has a huge potential of getting larger when placed on a large Live Rock.

Lighting Requirement

Acanthastrea Corals prefer medium lighting with some shade to maintain their lustrous colors.These Corals don’t do well in high-intensity lighting.

Placing your Acan in the middle of the tank or lower can help reduce light intensity and prevent stress to the Coral. Acans are less likely to open up fully in bright lighting.

A photosynthetically active radiation (PAR) level of 30-50 is considered moderate. A PAR closer to 90 is too intense for most Acans.

Avoid strong lighting, depending on the species, it may prevent the polyps from opening up fully, cause the loss of coloration, or even worse – bleach them.

For example, high light can even cause a loss of blue pigments and a deepening of red pigments.

Be ready that the coloration of Acans Corals in the store will be different in your set up.

Water Flow

Flow is important for all corals as most are Filter Feeders.

Acanthastrea Corals prefer a water flow with a medium current.

Be sure when you are placing your Acan that you don’t place the Coral directly beneath the Reef Tank’s Pump Overflow.

This Coral does not tolerate direct current well. Proper Water Flow helps suppress the build-up of Carbon Dioxide that can eventually affect your Tank’s Alkalinity levels.

It also helps remove excess waste through circulation into the Filter.

The current created by Water Flow helps imitate a coral’s natural oceanic environment, while the Coral uses lighting for Photosynthesis to Feed itself.

Water Parameters

Acan Corals will appreciate standard Saltwater Parameters, they won’t tolerate high drastic changes in water chemistry regardless of their hardy nature.

A high standard of water quality is key to a healthy and successful Marine Aquarium.

Lots of health and algae problems are caused by unstable water quality.

Water Changes of 10% bi-weekly, or 5% weekly is needed for tanks housing Acans.

Monitor your Acans Corals on a regular basis, that way you can easily discover and tackle any problem that arises quickly.

Required Range for Acan

Salinity : 1.024 - 1.026                                                                     

Temperature : 72-78° F

pH: 8.1-8.4

Alkalinity : 8-12

Calcium : 400-450ppm

Phosphates : 0,05-0,2

Nitrates : 2-20ppm

Magnesium : 1200-1350

Strontium : 8-10

Acan Corals are pretty sensitive to Phosphate levels in the tank. Once you get too much, they often shrivel up.

In this case, do a Water Change and stop feeding them for a week. They should open back up gradually.

Diet / Nutrition

Acanthastrea, like nearly all Corals, have symbiotic algae in their cells called Zooxanthellae.

These algae Photosynthesize within the Coral Polyps and provide important sugars for the Coral’s energy and growth requirements.

They are also responsible for most of the color and fluorescence of the Coral.

However, regular feeding should be a priority, they should be fed every 2 or 3 days.

You can feed them at any time of the day regardless, Acans will accept the following meals: Copepods, Shrimps & Meaty Foods, Frozen Mysis, Marine Pellets.                                                                                                        

The best time of day to Feed Acanthastrea Corals is in the evening. At night, the feeding tentacles of the Coral Polyps come out to forage and the Corals will be extra receptive to taking up food.

When feeding, be sure to squirt the Nutrient solution over each Polyp to ensure that each part of the Coral Colony has a chance to feed.

Bear in mind that Corals newly introduced to the tank may not accept food for a while, this is quite normal, they will only commence feeding when they have fully acclimated and settled in their new environment.

Maintaining a regular feeding schedule is important in an Aquarium with multiple Corals since not feeding often enough can lead to competition and increased aggression between Corals.

Fragging / Propagating

Acan Corals can reproduce both sexually and asexually. In captivity, Corals can be reproduced by fragmenting or “Fragging” them and breaking them into multiple pieces. Fragging (propagating) your Acan Coral shouldn’t be too much of a challenge if you know how to do so. 

The only issue is that you’ll likely need some specialized equipment like a band saw, because due to its shape, Acan is a bit difficult to frag using normal cutters.

Other than this, Fragging Acan is pretty straightforward. Cut the Coral as desired, give it a dip in water with a disinfectant like Iodine and superglue it to a Frag Plug or some Rock.

It should usually recover just fine and keep growing as usual.

Acan Corals grow pretty fast.

It is not uncommon to notice new heads forming only a few weeks after cutting a new Frag. there is no space left, the growth rate slows down and they start growing by excreting more skeleton and mounding into a larger shape.

Pests / Diseases

Acans are generally Hardy Corals.

If your coral does not fully extend or begins to recede and expose its skeleton, or starts to bleach (loose color), these are signs of stress.

You should take steps to determine which of the above stimuli are causing the stress.

Start by measuring your nutrient levels and determine if your organics are too low.

Next, you can change the flow or lighting by adjusting equipment or moving the coral to a new placement.

Try to only change one variable at a time. If there is a change in behavior, you will know which variable caused it.