Ultra Red Acan

Acan Corals tend to prefer the lower side of lighting intensity. Provided the PAR is at least 25-50, you should be fine. You may need to experiment with what the particular Acan coral likes best.

As for flow and placement, there are a couple of things I look for. Micromussa do not require a ton of flow, so I look to provide just enough so detritus does not settle on them. Most of the time hobbyists place Micros towards the bottom of the tank so it is important that they get enough flow to keep them clean. On the other hand, I think feeding is important for long term health so preferably the flow can slowed during feeding time to allow the coral to grab pieces out of the water column.

Acanthastrea Coral Feeding: The Acanthastrea genus, like other large polyp stony (LPS) corals, have developed several feeding strategies. Through a symbiotic relationship with a marine algae, known as zooxanthellae, they receive some of their nutrients. They also capture planktonic organisms, food particles from the water column, and can absorb dissolved organic matter.

 In captivity, A. echinata feed mostly on nanoplankton and dissolved organics in the water, though like Ricordea (a type of Mushroom Coral), they can be fed zooplankton and very small prey.