what does it mean if a coral turns brown?

[Milad]

I got SPS birdsnest that is brown. I was told it was purple but seems really brown than purple. What does that mean?

[tang daddy]

when a coral browns it is usually because of excess nutrients, But when acros get moved to a different system and turn brown it is getting use to its new enviroment. I've had frags stay brown for up to 1 yr before colouring up.

When the sps get stressed from a new system or high nutrients it will drop it's zooanthelia basically dropping some of it's colours.... it can regain colours but needs time. Low nutrient systems have brighter colour sps because they dont feed on nutrients as much, also sps use light to convert it to food which forms on their body in a brownish colour....

You can do a search on google to find out more on how these animals feed, grow it's really amazing....

[Blue World Aquariums]

Typically excess nutrients (nitrate and phosphate), or not enough light. Either condition causes the population of zooxanthellae (a brown algae in the coral tissue) to increase. The zooxanthellae is brown, and can overpower the color of the coral.

[ScubaSteve]

+1 on not enough light and being new to your tank.

I rescued an acro from someones tank that was completely bleached. I stuck it in my tank and within a few months it took on the craziest colouring (I've never been able to ID it). However, about a month and a half ago I moved and set-up a new tank and the mystery acro temporarily got relegated to a dark corner of the tank. Between the move and the low light it went so brown that in the low light it looked black. I have recently moved it back to a high light area and it's colour is slowly coming back.

Corals can regulate their zooxanthellae levels depending on their needs. In low light they need more algae zoox (which are brown) for energy, so they up the zoox level and look brown.

[Milad]

well this guy is about 8inx6inx6in birdsnest and it was brown when i got it. its been around 2months in a high flow high light are in my tank. about 12-13in from 150w MH

[sphelps]

The brown is zooanthelia and in simple terms is just a form of algae and can be treated as such. It can take a long time top get rid of the brown, just imagine if you had a rock with hair algae on it and couldn't use a clean up crew or manual removal, it would obviously be tough to get rid of it.

But there is hope, SPS need tonnes of light to really color up, the color pigment can be viewed as sunblock, the brighter the light, the brighter the color. Your lighting source is on the very small side and way to far away from this type of coral, so moving it up would be the first step and if you plan on pursuing SPS then an upgrade will be a necessity. You can also try a zooanthelia remover like Zeo Spur 2, when used properly it essentially wipes out all zooanthelia in the coral allowing to start over fresh. However just like other algae it will come back if the conditions aren't right.

[marie]

Or, if it was brown when you got it, then it could very well be.....a brown birdsnest.
Different lights can make corals appear to be a different colour then what they actually are and if the coral was in a tank with a lot of bluish light then it may well have appeared purple to some

[Ross]

What do you mean if a coral turns brown... I though thats how they all look... ...at least in my tank.:bad-word: