It's not just for doctors either.

I'm not that professional but I think a whole house filter would filter particulates like dirt but not chlorine. for chlorine you might need a reverse osmosis system for a specific drinking water tap to eliminate the taste as it's not practical or efficient to put an RO on the whole house supply. if skin issues from bathing are a problem you might need a softener. sometimes when kids have eczema doctors actually prescribe "bleach baths" where a small amount of chlorine bleach is added to the bath water. also many of the water treatment systems can be rented so maybe just rent it while they are there. regardless, proceed with data. water test, pediatrician diagnosis (if it's legal to ask for, no clue), and a system that is right for the application. sounds like the tenant is willing to help out which is awesome.

You could go many different ways with rentals such as student housing, section 8, targeting specific renters such as traveling nurses/doctors.

Just some additional companies for you to consult with in the Indianapolis area -- Hitman Solutions (former contractor at Michaelis) - Acculevel, Jaco, Crawlspace Doctor  -- PM  me if you need phone numbers

Problem with them is they live in two worlds with fear and anger ; but we're not their doctor.

Do you get to negotiate your doctor's fees?

Have you looked into extended stay STR for 31 days and over for corporate rentals and people on short term assignments and contracts such as engineers, doctors, nurses, etc. that travel and stay for 3, 6 or 12 months only? 

These examples were both smart people mind you (one an engineer, the other a doctor).

I would even require bank statements, schedules, regular doctor visits, job searching or physical therapy or efforts to become self-reliant, etc. as a condition of SSDI -- partying, alcohol, drugs, smoking could revoke their SSDI.

We would previously see many travel nurses and doctors come through the area, but that may be going away completely.