Favia & Favites: Brain Corals — ID, Care and Frags for Sale

Favia and favites are the encrusting brain corals — rounded corallites packed across a dome, in contrasting eye-and-rim color combinations that look machine-printed under blue light. They are among the most durable LPS we grow, and among the most underestimated: a colony that starts as a 2″ frag will slowly tile its way across whatever rock you give it.

Favia or favites? Look at the walls

The difference is structural. Favia corallites each have their own separate wall, so there is a visible groove between neighbors. Favites corallites share walls, so the pattern reads as a continuous honeycomb with no gap. Look at where two polyps meet and you have your answer. The trade sells both as “brains,” our listings name which you are getting.

Care at a glance

The care is easy; the neighbors are the catch. Both genera send out sweeper tentacles after the lights go off that will burn a coral several inches away, and you will never see it happen — just an unexplained dead patch on whatever sat closest. Leave real space around a favia the way you would around a torch.

They sting harder than they look

A favia sitting flat on the rock in daylight looks like the least threatening thing in the tank. After dark it puts out sweeper tentacles several times the length of anything visible during the day, and it uses them. Favia are a common cause of the mystery burn on a neighboring coral that somebody blames on flow or lighting for a month.

Give a favia frag more room downstream than seems necessary. It will encrust outward from wherever you glue it, so the animal that gets stung is usually the one you placed later, on the assumption the favia had stopped moving.

Why yours went brown

This is the most common thing people ask us about favia, and it is almost always the same mechanism. The coral is carrying more symbiotic algae than it needs, and their brown pigment sits on top of the colors you bought it for. Two things drive it: more nutrient than the animal is using, or less light than it expects, and often both at once because a shaded coral compensates by growing more algae.

The fix is not a product. Move it up or brighten the spot it lives in, get nitrate and phosphate to a stable moderate level rather than a high one, and give it a couple of months. Colors come back slowly and from the edges in.

What does not work is stripping nutrients to zero to chase color. A favia in a tank with no nitrate pales, then bleaches, and the color you get on the way is not one you keep. Stable and moderate beats aggressive in both directions.

Feeding, and the tentacles you have never seen

Favia feed at night, and most people never see it because they never look. An hour after the lights go out, a healthy colony has fine feeder tentacles standing up off every corallite. Put a small meaty food in front of it then, with the pumps down, and it will take it.

You do not have to. These are among the more forgiving LPS and they will grow on light and whatever the tank provides. But feeding is where the growth rate changes from tiling slowly to visibly claiming rock, and it is the cheapest thing you can do for a colony you want to get big.

What to look at before you buy one

Look at the growth edge. A favia that is doing well has a thin band of fresh tissue creeping onto bare plug or rock at the margin, usually paler than the rest. A colony with a hard, sealed edge and no new tissue has been static, and static is information.

Then check between the corallites for bare skeleton. On a healthy favia the tissue runs continuously across the whole dome. Gaps mean recession, and recession on an encrusting coral spreads across the surface rather than up from a base, so it is easier to miss and harder to stop. Ours are photographed in our Key West systems, and on a WYSIWYG listing the photo is the exact animal that ships.

Favia and favites in stock now

One thing to know before you order: the $10 Box & Handling Fee is charged by the box, not by the coral, and UPS Next Day Air is one flat shipping charge per order. A box holds several corals for the same $10 Box & Handling Fee and the same overnight ride, Florida orders under 6 lb ship UPS Next Day Air for a flat $30, and livestock orders of $349 or more ship free. If this page puts one coral on your list, it is worth seeing what else belongs in the box — start with corals under $100 or the newest WYSIWYG pieces.

Our stony corals are either aquacultured at the shop in Key West under Florida Aquaculture Certificate #AQ0254072 or conditioned in our Key West systems before they ship, and the photo on a WYSIWYG listing is the exact animal that ships. Corals ship UPS Next Day Air every Tuesday and Wednesday. If you are ever in Key West, come see the raceways.