Really want to know what these are

[Zakwhite]

What are these they have been in my tank ages im guessing its something to do with snails but not sure please help!

 

[kdpuffer]

They look like pieces of some type of leather coral. In the first pic I see a small toadstool leather so my guess is that is what kind. Leathers often drop chunks off that then grow into new ones. If that is the case here you will have a whack of leathers.

 

[kdpuffer]

After lookin again they could also be sponges.

 

[Zakwhite]

They look like pieces of some type of leather coral. In the first pic I see a small toadstool leather so my guess is that is what kind. Leathers often drop chunks off that then grow into new ones. If that is the case here you will have a whack of leathers.

Defo not leathers that leather below just blew there and I moved the rock from a couple of days ago if I place a rock near it or on it it attaches it self is that what sponges do? It's all around the tank and was like in the filter and stuff on and in the filter tube??