tiny fan shaped algae and black vermatid snail?

[errand]

I have just upgraded my lights to AI prime HD and have suddenly spotted a lot more things in my tank - the lights are amazing - but there are 2 that I'm not sure about. 

There are tiny tiny little green algae looking things in a patch of zoas - they are like a fan palm, with a main trunk and then a fan branch. But tiny - like 2mm tall. 

They are way too small to pick off so I hope they're not dangerous. 

The second thing I have found is what looks like a jet black vermatid snail - little coiled shell and two little antennae. It doesn't seem to be casting out fishing lines yet though. This guy i could probably pinch off but I don't want to kill him if i don't have to.

Also in the same cluster - there is a very tiny thin translucent thing with a star shaped head - its quite long, about 5mm long, but looks very delicate - is this a hydroid? It's in the bottom right of the picture, but my phone camera can't quite get a good view even with the new lights.

[minimal]

Not sure on the last two, but the algae is Caulerpa verticillata. The algae itself isn't dangerous, but left unchecked might choke those zoas out.

 

If you'd like to get rid of it, I'd do a blackout period, manually remove as much as possible, and water change. If you leave it in, just be aware that caulerpa can grow extremely fast in the right conditions 🙂

[errand]

Ah thankyou that's great information. I've read about caulerpa taking over tanks. It is truly tiny at the moment i might wait until it's bigger as that frag is cemented to the main rock 😞 I can't get tweezers down there.

[minimal]

It can, just be diligent in removal/water quality and it will be alright! Good luck 

[Joevember]

Looks like you were right, the last two are a vermetid snail and a colonial hydroid.

[mndfreeze]

Last two are definitely a vermetid and hydroid.  

[johnmaloney]

On 7/18/2019 at 10:08 PM, errand said:

I have just upgraded my lights to AI prime HD and have suddenly spotted a lot more things in my tank - the lights are amazing - but there are 2 that I'm not sure about. 

There are tiny tiny little green algae looking things in a patch of zoas - they are like a fan palm, with a main trunk and then a fan branch. But tiny - like 2mm tall. 

They are way too small to pick off so I hope they're not dangerous. 

The second thing I have found is what looks like a jet black vermatid snail - little coiled shell and two little antennae. It doesn't seem to be casting out fishing lines yet though. This guy i could probably pinch off but I don't want to kill him if i don't have to.

Also in the same cluster - there is a very tiny thin translucent thing with a star shaped head - its quite long, about 5mm long, but looks very delicate - is this a hydroid? It's in the bottom right of the picture, but my phone camera can't quite get a good view even with the new lights.

 

The algae looks like Rhipidosiphon species:

 

https://www.researchgate.net/figure/6-Rhipidosiphon-lewmanomontiae-General-morphology-HEC-16223A-3-Juvenile-plants_fig3_215888433

 

Calcified algae, will be harder to remove than you would like. They are related to mermaid fans, but stay small. Plucking them would be effective.