Advice on Pre-Screening Tenants

[Account Closed]

I just recently listed my home for rent.  This will be my first time being a landlord.  In my ad for the rental, I set some guidelines that should help weed out some undesirable tenants.  The criteria I listed is 

First & Last months rent plus a security deposit, which is equal to the rent price.  

650 credit score minimum

No pets

The HOA that governs the property also requires a background check and credit check as well. The property is a 3B/2.5BA Townhouse located in a B neighborhood in Broward County, FL. I just posted the property for rent this past weekend and have received a lot of interest. However the problem I keep running into is that no one is able to meet my minimum credit score requirement. Like i said before, this is the first time I've listed anything for rent. Is 650 too high of a requirement? Should I go with a lower score? What are some other methods I can use to help determine whether a tenant will pay the rent on time. I am also requesting for applicants to send last 3 paystubs for proof of employment as well as references from past landlords. I'm also curious to know if this is just an issue for my specific market or is this something landlords deal with nationally?