Put aside half for unexpected fixes.

We generally don't allow new pets into a house if they didn't have one when they leased, because that generally means either a puppy or a rescue and either one is going to be more prone to accidents in the house, chewing on things, etc. 

One time it took me 6 hours to get to Richmond because of 3 car accident in the summer.

It will also screw you over if you come across unexpected expenses.

@Kristopher TurskyAlso be sure to keep extra cash on hand as a cushion just in case any unexpected issues come up.

What if you have an accident that makes you unable to work?

Unfortunately I'll probably end up banking on some appreciation as well, since my early guess is that the cash-flow, while positive, is too thin to completely cover a large, unexpected CapEx expenditure. 

The month where the furnace craps out and is -$1,500 cashflow with $500 principle paydown or the month where you have no unexpected expenses?

If you didn't build one into the lease, calculate the unexpected costs of turnover at an unplanned time.

Our plan was to move a nicer & newer fridge from a neighboring vacant unit into this tenant's unit and then replace the poor performing fridge as time permits prior to the vacant unit becoming occupied.However, the tenant has now refused to accept the refrigerator from the vacant unit because the previous tenant (of the vacant unit) recently died in a car accident, and the receiving tenant has sited a STRONG fear of ghosts as her reason for refusing our solution to her refrigerator complaint.