Snails came with this on its shell, should I add it to the tank?

[GreyYeti]

Just got these snails however looks like somethings growing on its shell, don't know what it is. Any input?

 

[G Santana]

Looks like Marco algae, just clean it off the shells.

 

[dwair]

Should be fine, but pick it off if you want.

 

[DrZoidburg]

Looks like a gracilaria sp. to me

 

[Goaway]

I'd keep the algae. Its not as invasive as gha.