It grows in one location because there's excess moisture allowing the mold to take proliferate.The first step is to figure out the source of moisture.

Does anyone have advice for the following:Is it a good idea to explore whether to rent out multiple rooms in single-family residences for the purpose of acquiring adequate cash flow:Does BiggerPockets Pro provide a way to find demographical data on specific sources and motivated sellers?  

These are my primary source of income.

These are my primary source of income.

These feel very direct sourcing and closing tactics.What you mention mentee #2 doing is very top of funnel items.  

The tried and true source of "have to sell".   

I used to source off market deals for investors and have done 25,000+ cold calls.

@Brandon Croucier - thanks for the response. what source do you like for background checks?

You should have been planning from the start to pay the HELOCs out of your regular income sources not the rentals.

Here's a summary of what you need to know:Population greater than 1M and growth rate: The source for metro population size and population change: WikipediaCrime.Operating costs: State income taxes are a good indicator of government efficiency.