Any guesses what these are?

[xCROv]

These guys are kinda all over the tank. They don't seem to be doing anything wrong, not sure if they are filter feeders or what. They look attached to the rock at one end and flail around until something touches them. I've seen them bump into the rock and grab on, they then let go (tail still attached) and will shrink a bit before expanding out to flail around in the flow.

They're about an inch long and only seem to attach to non-glass hard surfaces like my rocks.

 

[KrisReef]

Look like hydroids but the movement you describe isn't typical for those?

 

[xCROv]

Look like hydroids but the movement you describe isn't typical for those?

Think you're actually right. I thought hydroids were not as thing and long like this but I think they're actually digitate hydroids.

Possibly these.

Digitate hydroids spreading. What to do?

I've got a Fluval edge 6g nano that's been up and running about 5 weeks now. No fish, just CUC and random hitchhikers. I noticed the first couple of d.hydroids a couple weeks ago isolated to one rock. They have since spread to most of the other rocks. Not infestation levels yet, but a good 6-7...

www.reef2reef.com

 

[KrisReef]

Think you're actually right. I thought hydroids were not as thing and long like this but I think they're actually digitate hydroids.

Possibly these.

Digitate hydroids spreading. What to do?

I've got a Fluval edge 6g nano that's been up and running about 5 weeks now. No fish, just CUC and random hitchhikers. I noticed the first couple of d.hydroids a couple weeks ago isolated to one rock. They have since spread to most of the other rocks. Not infestation levels yet, but a good 6-7...

www.reef2reef.com

Post 8 in that thread says they will go away, and feed lightly to starve the little filter feeders. I wonder if using a flocculant (can't remember what people DYI on here for that) would also be helpful. I had them many years ago, different kind and they dissappeared quickly.

 

[xCROv]

Post 8 in that thread says they will go away, and feed lightly to starve the little filter feeders. I wonder if using a flocculant (can't remember what people DYI on here for that) would also be helpful. I had them many years ago, different kind and they dissappeared quickly.

I'm wondering if it's worth worrying a ton about if they're not causing any issues so far. Probably going to just keep an eye on them and address them if they end up causing any other problems to the rest of the tank. They get a pass for now.