Weird appendages growing out on rock?

[Cole_Voeller]

These started growing on my rocks a few weeks ago, theyve spread a fair bit. No idea what they are. Anybody know, and are they harmful?
Thank you!

 

[jabberwock]

I see a lovely little feather duster, and then some snot arms. Not likely much you can do about the snot. Possibly vermetid worms. Look for a hard shell twig sort of thing. Crush them if you can.

 

[Cole_Voeller]

I see a lovely little feather duster, and then some snot arms. Not likely much you can do about the snot. Possibly vermetid worms. Look for a hard shell twig sort of thing. Crush them if you can.

I tried looking online, apparently these are Digitate hydroids? And apparently these are absolutely horrible for my tank. No idea what to do about them.

 

[Gtinnel]

I used to have digitate hydroids in my tank and they would occasionally pester corals but otherwise never really caused any harm. They eventually seemed to go away on their own and unfortunately I can’t say what caused them to die off in my tank.

 

[Cole_Voeller]

I’m going to put my peppermint shrimp in, as well as my hermits and see if they do anything to help. I’m also going to super glue any that are in easily accessible spots.
This might be a dumb question, but can I use frag glue underwater? Or do I need to remove the rock first?

 

[Gtinnel]

I’m going to put my peppermint shrimp in, as well as my hermits and see if they do anything to help. I’m also going to super glue any that are in easily accessible spots.
This might be a dumb question, but can I use frag glue underwater? Or do I need to remove the rock first?

AFAIK any glue that you can use on frags can be used underwater. The most common being superglue gel or the 2 part coral epoxy putty and either are fine to use in the tank. Sometimes the superglue gel has to be smeared around to get it to stick because in the water it will instantly form a skin on it.

 

[Udest]

The hydroids will go away on their own , don't worry about the feather duster.

 

[Tired]

If you want to superglue over something, take the rock out of the water and put a drop or two of liquid, not gel, superglue on top. Works pretty well for aiptasia, should work on just about anything else. Does require a little luck, though; if the critter is deep in and has another hole to pop out of, the glue may not work.

That said, the hydroids are likely fine, and the feather duster is harmless/neat. No glue needed here.

 

[EeyoreIsMySpiritAnimal]

I tried looking online, apparently these are Digitate hydroids? And apparently these are absolutely horrible for my tank. No idea what to do about them.

Colonial hydroids are the bad ones. Digitate will come and go, but as others have said, aren't usually a problem.

 

[AydenLincoln]

Feather duster and digitate hydroids.

 

[Cole_Voeller]

Colonial hydroids are the bad ones. Digitate will come and go, but as others have said, aren't usually a problem.

Okay. I was freaking out since a lot of people online have said that they sting and kill zoas.

 

[elysics]

Okay. I was freaking out since a lot of people online have said that they sting and kill zoas.

Many hydroids will kill most anything they touch. So will many corals with their sweeper tentacles. The question is whether they spread so fast/wide that the resulting dead zones are a problem at all.

The problem with colonial hydroids is that they cover rock like a mat creating massive dead zones and can't really be ripped out successfuly.

Thesw here can be ripped out if they bother anything, more of a nuisance than a danger

 

[Tired]

Don't put any zoas directly on the hydroids, and you're good.

 

[EeyoreIsMySpiritAnimal]

Okay. I was freaking out since a lot of people online have said that they sting and kill zoas.

Well, yes, they can do that... But it's not like they hunt coral down, lol.
Hydroids sting.
Not all hydroids grow en-masse like colonials do, potentially taking over large parts of the tank.

Edit: @elysics said it better... I didn't read before I posted

 

[Cole_Voeller]

Many hydroids will kill most anything they touch. So will many corals with their sweeper tentacles. The question is whether they spread so fast/wide that the resulting dead zones are a problem at all.

The problem with colonial hydroids is that they cover rock like a mat creating massive dead zones and can't really be ripped out successfuly.

Thesw here can be ripped out if they bother anything, more of a nuisance than a danger

Some are pretty near where I was going to place some zoas, so I would like to remove them. Can I just grab the tentacle and yoink it out and kill it like so? Or do I need to remove the entire thing stalk? I only ask because some of them are in pretty tricky spots, and removing the rock isn’t an option, which will make it harder.

 

[EeyoreIsMySpiritAnimal]

Some are pretty near where I was going to place some zoas, so I would like to remove them. Can I just grab the tentacle and yoink it out and kill it like so? Or do I need to remove the entire thing stalk? I only ask because some of them are in pretty tricky spots, and removing the rock isn’t an option, which will make it harder.

I really wouldn't worry about it. The ones you see now will probably die soon and you may or may not even see them again. If you see one bothering coral that's already in the tank, then yes, you can pull it out, smother it with kalk or glue, or just put another small rock between it and the coral.
They really aren't a big deal

 

[Cole_Voeller]

I really wouldn't worry about it. The ones you see now will probably die soon and you may or may not even see them again. If you see one bothering coral that's already in the tank, then yes, you can pull it out, smother it with kalk or glue, or just put another small rock between it and the coral.
They really aren't a big deal

You got it, thanks for the insight!

 

[EeyoreIsMySpiritAnimal]

You got it, thanks for the insight!

We want updated pics when you get all your coral in!

 

[Cole_Voeller]

We want updated pics when you get all your coral in!

Will do! Here’s what it looks like at the moment, before I add them.
It’ll just be zoas, Sympodium, and some mushrooms. Maybe some other soft corals as well. I’m not too great at aquascaping and I didn’t really want to glue everything, so I think it’s decent? XD

 

[EeyoreIsMySpiritAnimal]

No fishies?