Sebae Anemone question

[Llyer]

I bought a sebae anemone yesterday and he was moving around and flipping himself up side down. I read on here that it's not good for them so I righted him. But he moved again so I just let the little guy do his own thing.
When I woke up this morning he was behind a rock upside down and completely deflated. So I moved him where there was a better current in the sand.
I noticed he has something attached to him today and I am not sure what it is. I kinda wonder of my shiny emerald crab (he is pink lol) got a hold of him.
If anyone can help explain what this is and also what I should do to make him happy and comfortable I would be very grateful!
Oh some info on my tank.
40 gallon breeder
Seacham water filter/skimmer
22 inch Fluval led light with Bluetooth
Sand bed with live rock and a few sea shells.
2 Clown fish, 1 Emerald crab, and 1 Sailfin Tang.
I plan on slowly introducing coral and leafy plants when I find some.

 

[ryanjohn1]

Here’s a quick google I did.

 

[ryanjohn1]

That particular nem may not have been the best choice for a tank on the newer side. Are you regularly checking your water parameters like alk, nitrate, and phosphate.

 

[Llyer]

That particular nem may not have been the best choice for a tank on the newer side. Are you regularly checking your water parameters like alk, nitrate, and phosphate.

Yeah I check the water twice a week my self and then I have it tested at the pet shop at Ace every Saturday and so far my water is really good.
I have been doing 10% water changes once a week. I did have to add a water heater to get my temp up to 81 degrees though.

I think he finally found a good spot because he is all puffed up and in the same spot for almost two to three hours now.

 

[ryanjohn1]

Yeah I check the water twice a week my self and then I have it tested at the pet shop at Ace every Saturday and so far my water is really good.
I have been doing 10% water changes once a week. I did have to add a water heater to get my temp up to 81 degrees though.

I think he finally found a good spot because he is all puffed up and in the same spot for almost two to three hours now.

81 may be a bit high. And is your sand deep enough for it to burry its foot?

 

[Llyer]

81 may be a bit high. And is your sand deep enough for it to burry its foot?

It's about 2inch deep, should I add more?

 

[ryanjohn1]

It's about 2inch deep, should I add more

It's about 2inch deep, should I add more?

 

[Llyer]

Thank you, I will definitely add more sand!