Pest on my zoa and leather coral

[Smartinelli]

Hey everybody. I noticed a pest on my bam bam zoa and my toadstool leather. I haven’t noticed this on any of the other corals even those in the same frag rack as the leather. I’m not sure maybe it’s some sort of hydroid. I noticed it on the leather a week ago and it looked a lot like how the zoa looks now. Any help identifying this as well as how to get rid of it would be appreciated.


I have to admit I have been neglecting this tank while I’m working on getting the new tank up and running and my nutrients are high causing the algae in the zoa.

 

[ISpeakForTheSeas]

The one on the leather is for sure a sponge - I would assume the one on the zoas is too, but I can't say for sure with the pic.

Yeah, that's definitely a sponge. Most sponges are completely harmless/beneficial, but some can be invasive and/or harmful to corals (thankfully, these are rare).

To tell if a sponge is chemically harmful: if a healthy, established coral starts closing up or looking to be in bad shape on the side closest to the sponge as the sponge grows closer to it, and nothing else has happened (lighting changes, parameter swings, pests, etc.) that could explain it, then the sponge is probably chemically harmful.

Chemically harmful sponges are very rare.

For invasive sponges: unless it shows signs of being chemically harmful or starts actively growing over and smothering a coral's flesh/polyps, it's harmless. These can grow over the skeletons of corals, around the base/stalks of corals, even up into the water column above corals (where they're over the coral but not growing on the flesh or polyps themselves), etc. without harming the coral at all - as long as the coral flesh and polyps can get food, light, and flow, the sponge is harmless.

Invasive sponges are moderately rare.

Invasive and chemically harmful sponges are incredibly rare.

 

[Smartinelli]

The one on the leather is for sure a sponge - I would assume the one on the zoas is too, but I can't say for sure with the pic.

Thank you. Glad it just sponges. I was thinking it was something more sinister.