Looks like hot and cold (blue and red valve knobs on the left side of the manifold.)Can't see it clearly but it the other one may be a pressure guage on a valve.

Looking to buy your house in cash.None of the pressuring techniques like "ohh I only have room for one more house to buy" crap. 

Anyone with a lot of cash and under pressure to do a  deal is in a vulnerable position, and having that knowledge cuts down the extent of how vulnerable you are.

After that you start seeing low pressure and more and more leaks.

Use s pressure test for plumbing, generator for electrical.

(Peer pressure?)

We divide the rent by 30 days, put that number in the lease and explain how proration works to make sure all are clear on what is and what is expected.Think about it... if all landlords worked that way, there might be less than a month's lost rent, less pressure, and more convenience for rent-ready work and tenant move in, rather than being so constrained by "THE FIRST!" 

We are in Mount Dora (just north of you) and have done a good amount of flips and currently have a handful of single family rentals.

Is this in Mount Vernon? 

That causes a lot of pressure in the area with your leaks and would account for the dirt you see around them.