Anyone know what this is?

Well thanks for clearing it up for me. I've seen aptashia in my friends tank but he never let his get this big and his looked diffrent. I got some shrimp on order and they should be here tomorrow. I just hope these things aren't too big for them to eat. Either way I'm super excited to be getting some peppermint shrimp!

 

that one looks big enough to pluck off lol thats a thick one

 

Probably looks different than his cuz it's been eating well LOL.
Not sure the peps will eat one that big.

 

No go on the shrimp. They are monsters tho these things are huge for a shrimp. They have not shown any interest in the aptashia. They are even bigger now that I moved them to the closer to the top of the tank.

 

I have always had luck with injecting them with boiling water. Same concept as the lemon juice, you suck up boiling water and inject it. I have also used super glue to cover their hole – which works well most satisfying if you glue a coral over its hole at the same time

 

As stated above, it is aptasia. For that big aptasia, I would inject it with Aptasia-X, but also get a couple of peppermint shrimp to consume smaller aphasia that you might not notice right away. They're fast reproducers.