ID Please!

tphan · Jan 28, 2023

What are these icicle/crystal like things on my rock? They are the size of a pin, from a quarter to half inch long. Does anyone know what they are or what negative impact they will have?

ISpeakForTheSeas · Jan 28, 2023

tphan said:
What are these icicle/crystal like things on my rock? They are the size of a pin, from a quarter to half inch long. Does anyone know what they are or what negative impact they will have?

Those look like sponges to me, so they probably won’t have any negative effects (rarely, people get invasive sponges that grow over and smother corals, but the vast majority of sponges are harmless/beneficial filter feeders - and the invasive ones typically become pretty obvious pretty quick).

tphan · Jan 28, 2023

ISpeakForTheSeas said:
Those look like sponges to me, so they probably won’t have any negative effects (rarely, people get invasive sponges that grow over and smother corals, but the vast majority of sponges are harmless/beneficial filter feeders - and the invasive ones typically become pretty obvious pretty quick).

Sponges? I am not very familiar with all the different types of sponges. These are sticking out of the rock work like needles and I see more and more of them each day.

ISpeakForTheSeas · Jan 29, 2023

tphan said:
Sponges? I am not very familiar with all the different types of sponges. These are sticking out of the rock work like needles and I see more and more of them each day.

Yeah, some sponges grow that way - here are some links to threads with similar ones: