Torch Coral Releasing Brown Slime – Is It Pooping?

Have you noticed your torch coral releasing “yukky” brown slime, and are unsure if you should be worried?

The first time your torch coral releases a brown slime, you may freak out because it looks pretty scary! Your coral’s head will likely shrivel up and a long stringy brown mucus will be expelled.

This process is a fairly common occurrence and has got reef hobbyists going crazy on forums everywhere, over why it happens. “Is it poop?” “Is it normal?” “Is my torch coral dying?”. All these “worries” you and other hobbyists go through when a torch coral is seen releasing brown slime, will shortly be cleared up (pun intended)!

Do Torch Corals Poop?

Brown excretions from an animal are usually poop, but do corals poop too?

Yes, corals can poop, and it comes right out of your torch coral’s “mouth” as they only have a single opening that serves as both a mouth and anus, so what goes in, must come out! Pooping is particularly common if you feed your torch coral. 

Brown slime can also be a sign of your torch coral expelling excess zooxanthellae. Corals can regulate zooxanthellae populations within themselves, occasionally releasing excess zooxanthellae even when healthy. 

Check out this golden torch coral pooping.

Once your torch coral has excreted its waste, give it 24 hours to recover – it seems to be quite an exhausting time for your torch coral! Don’t worry if it closes during this time, this is also normal behavior. If your torch coral does close up, this is also a good time to check if its tissue is receding, if so, it may be brown jelly disease. 

Sometimes people often confuse “brown slime” coral excretion with brown jelly disease. If your torch coral has brown jelly disease, you should remove it immediately, as it is a very contagious infection. 

If it is brown jelly disease your torch coral will be covered in a gelatinous, brown mush, and rapid tissue loss around the base will be seen. This is very different from a long string of brown waste that comes out of your torch’s mouth! 

Torch Coral Expelling/Discharging Zooxanthellae

The brown slime your torch coral releases could also be from excess zooxanthellae. 

Often corals will discharge zooxanthellae because they do not have a liver containing bile, which would usually help with the breakdown of food. When they discharge this brown slimy waste, it consists of leftover food. 

All photosynthetic corals (like your torch coral) must regulate the zooxanthellae population inside their tissues, and occasionally they may need to remove some. The usual reason behind this can be split into three categories: temperature increases, PAR increases, and excessive nutrients. 

Temperature Increases

Temperature increases are one of the most common stressors in reef aquariums. This is why corals bleach. When temperatures increase, the zooxanthellae, which provides your torch coral with pigmentation, is expelled from sudden stress. If the stripping of zooxanthellae continues, your Torch Coral will undergo coral bleaching, eventually turning white, and dying. 

PAR Increases

PAR stands for photosynthetic available radiation, which is related to the light intensity your torch coral is exposed to from your lighting fixture. 

If the PAR suddenly increases, the amount of oxygen produced inside your torch coral will also suddenly increase. When oxygen levels reach an all-time high, the inside of your torch coral’s walls become oxidized. In response, your torch coral discharges large amounts of zooxanthellae in one go, which could be the brown slime you are witnessing. 

This is very common when a new coral is added to an aquarium because they need time to acclimate to the new lighting; often you provide more lighting than it was receiving at the local fish shop, or wherever you bought it from, which is why it is always a good idea to drop them a message and ask what PAR level your frag was grown under. 

Excessive Nutrients

Reproduction rates of zooxanthellae are directly influenced by the number of resources available. Overfeeding your torch coral increases nutrient levels, which increases zooxanthellae reproduction. 

Even though the zooxanthellae is not producing excessive oxygen levels, your torch coral colony will, and the same result as above happens – in response, your torch coral discharges brown slime containing the zooxanthellae.

Should You Pull Off The Brown Slime?

You should never manually pull off brown slime released from your Torch Coral (or any coral for that matter) unless it is brown jelly disease, which in that case you can gently use a turkey baster (or pipette) to suck it off. Pulling the slime directly from its opening can damage your coral’s polyp, and in worse cases, tear polyps from its body. 

So, How To Remove The Brown Slime?

Your water flow should eventually wash it away from your torch coral. Once it has fallen off, you can take a pipette or turkey baster, remove it from the water, and dispose of it, unless your fish gets to it first!


If your torch coral is releasing brown slime it is most likely having a poop! Corals pooping is normal, and time should be given to your coral to do its business. 

If it is not poop, it may be zooxanthellae discharge, again this is relatively normal, as long as all your aquarium conditions are stable. Keep an eye on your torch coral for any abnormal changes, and if your torch starts receding at the base, it is probably brown jelly disease, which is a problem.

But all in all, brown, slimy, “goo”, should not be a cause of concern, it is a normal process, should your torch coral be nice and healthy

  • Roy Lee

    I have an unhealthy obsession with reef keeping and maintaining successful tanks. If you haven't noticed from the website, I love everything related to saltwater tanks like coral, fish, and everything else in between.

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