Help ID please

[Ryan Kraft]

Anyone know what these are? Have been searching online but haven't really found anything besides spaghetti worms but they don't really look the same.

 

[Don_Jorge]

ribbon worm maybe? It's kinda hard to see

 

[duberii]

If you're talking about the white stuff that's a sponge- it can grow quite fast but it's also pretty easy to get rid of via exposing it to air or injecting it with vinegar if you don't like it. It's harmless unless it's overgrowing corals though.