Made an offer and have questions!

[Bobby Beard]

I have owned several properties however i have never inherited tenants.. 

Made an offer on two tri's yesterday. All units are currently rented. 50% are a couple months into year lease and the other 50% are on month to month. The current rents are in the 500's, the rents need to be 700. The market would support 700 easily. 

My question is, can I and how do i raise the rents the day i take over? Has anybody dealt with this want to share your experiences? 

This property is in Florida.