Good or bad

[Ethanjordanu]

Hi there all just want to know if this is a good thing or a bad thing in marine tank? Tia

 

[TaahirS]

Those are bristleworms. They're great at eating leftovers.

Just make sure you don't touch it. Will leave some nasty little spikes in your hand.

 

[RiaanP]

Small ones, less than 10cm are very beneficial. The large ones you do not want to touch. Be careful when moving rocks. As they tend to hide underneath.

 

[CameL]

Or use non powdered latex gloves or similar.