what is this??

[4angel]

These guys are white tubes with green flourecent tips growing out from the rock. I see nothing that looks like an opening on top.
_________________
grape ape pics

 

[ErikS]

I don't know the scientific name, commonly called "catepillar weed" - harmless.

 

[Anonymous]

I had a few when my tank was new, but something ate them all up and won't let them grow back. They're kind of cool lookin' actually.

 

[horge]

Neomeris annulata. (possibly Neomeris vanbosseae)
Just another green marine alga. It accumulates calcium around the thallus. Nice to have a few around.

IF it starts spreading aggressively, eradicate without mercy and make sure NO algal material (the holdfast) remains on the rock. It usually hapens in systems with an excess of dissolved nutrient, so... keep an eye on nutrients as well.