The issue of water quality we haven't had but I did have a spring box house years ago (like a dug well)  and that needed a UV system. 

Over time the pipes become damaged as voids or underground air and water pockets form and either the house or the pipes subside, cracking the pipes.

Initially the rough plan was to sell when the properties doubled in value, especially if we could get to that point before any major capital expenditures. using that rule of thumb we can sell 2 in the spring (both have doubled or nearly doubled and are also the 2 with the most capital expenses coming up) and roll that into something in ATL and hold onto the other 2 a while longer.

Once in the spring and once in the fall, it also gives the tenants a peace of mind, and the perception that the owners care about the place.

or spring for a hard-money lender if I have the systems in place and a project timeline with deadline for filling vacancies.

If you have access to the Owner or his/her Agent, then it may be worth the inquiry: “what would it take to ask you to hold this for me until late spring?”

However, it is a musician, artist I will hesitate.Few people are interested in housing at this time of the year until next spring.

In the end, we just sold my husband's condo in Colorado Springs because it just made more sense to do that rather than refi to buy our triplex out here. 

Sure, if you want the extra stress/vacancy/costs that go with student accommodation or Air B&B, there's many who make great profits - but also - plenty who don't!

Yes, my first home had a boiler, the biggest drawback is leaves you dealing with window air conditioners more often than not.