Notice to Vacate after Closing in Florida

Hi All,

I am closing on a multi family property next week in the Florida Keys. The current tenants expressed interest in staying in one of the units. They have been living in the unit without a lease - because the former owners of the property employed the tenants. I will be increasing the rent and anticipate the tenants will decide to move due to the increase. What kind of notice to vacate would be used in this case? 

Thanks!

Dani