coral? mushroom?

I am talking about the mushroom looking thing in the left side of the picture. It had a smooth top, where "tenticals" would come out when it was in the light. It had a spongy texture to the stalk. I recieved it when I rescued the tank... I would love to figure out why it died and what I need to do to keep a new one safe... but first I have to figure out what it is!

 

That is a Toad Stool (Sacrophyton)/aka Leather Coral.

They will not open fully in tanks with a lot of algae, this leads to their slow demise.

As with most corals they require decent water quality and lighting.

Considered a soft coral that requires mod lighting and mod to higher flow.

 

Thanks...

LOL, I know better then to get one now... Just curious for the future... I have a different battle to undergo right now...

 

I think it looks like a rock anemone......

 

oops....my bad, I was looking on the right, DOH!

 

Toadstool. Fairly easy with decent params .. they like good flow. It was one of my first and also a favorite. They grow fast and are great to have. They quickly show you what they like and dont like.