Any idea what this is?

[Flame2hawk]

Came home to this after being away for 5 weeks? It’s spaghetti/stringy like accompanied by cotton puff type balls of fine hair growth. Not hair algae as it is not green. Never seen anything like it. Also have these moon crater type mounds in sand as shown in last photo. Any thoughts?

 

[Tuan’s Reef]

almost looks like Chaeto to me. Is it soft?

 

[Rick's Reviews]

Where does it come from? Meaning where is it growth/base (glad it's not only me with spirorbid problem)
Where is it starting from, where does it grow from

 

[Flame2hawk]

almost looks like Chaeto to me. Is it soft?

almost looks like Chaeto to me. Is it soft?

It does feel like chaeto but not green and it looks kike its coming or attached to the white hairy puff ball things….

 

[ying yang]

What is that!! A R2R guide to common new tank hitchhikers.

One of the greatest things about starting a reef tank is getting your live rock in and admiring all the diversity within it. The rock comes to life different creatures. This is a guide that I, along with a very well known critter identifier @KJ , have put together for the new reefer on what...

www.reef2reef.com

Benthic ctenphores/comb jellies maybe?

As you mention puff things

Guide to Common Hitchhikers in Reef Tanks

Guide to Common Hitchhikers in Reef Tanks by @A Young reefer The purpose of this thread is to hopefully assist hobbyists in obtaining the correct id and method of treatment to common hitchhikers. Both; the good ones and the bad ones. 1)...

www.reef2reef.com

Here another hitch hiker thread which mainly same but few additions ^_^

 

[Tuan’s Reef]

It does feel like chaeto but not green and it looks kike its coming or attached to the white hairy puff ball things….

Can you fish some out and take a pic under white light? curious to know what that is. I get weird looking stuff growing on my chaeto too.. but its mostly green hair algae.