to hard to be a sponge but cant be coralline

its been growing slowly but surly anyone know what it is?

i know just under it is some sort of smooth hard sponge but i guess getting more details would be harder.

 

Foraminaferan

 

Chances of survival?

 

+1

Not sure about its chances for survival, though.

 

It will depend on your tank's food supply. Generally they don't do well our tanks. I think there is a possibility that they do better in well established tanks but have no proof. I know when my tank was new that they did not survive long. Now that my tank is older and I am not trying to keep it as an ultra low nutrient system they seem to be doing better.

 

thx for the replies