Quote from @Craig Jones: For chemistry nerds:A salt water tub uses a cartridge with titanium plates in it.  

Here's a few things that help me: For macro industry trends, I like the STR Data Lab podcast by AirDNA and Jamie Lane. 

The right chemistry can accomplish incredible things.

Get there in person and find the house in a sink hole or wrapped in meth lab tape or some other huge issue not seen online.#5 There used to be a lady named Sandra Edmonds I believe and she went by the name of TAx Lien Lady. 

If you decide to go the multifamily route, Real Estate lab .com is a multifamily software for deal analysis plus they have many other useful features. 

@Jay Fayz for SFR (1-4 family) Classifications are mostly opinion-based.Not aware of anyone tracking eviction rates, except Evictions Lab nonprofit that doesn't like landlords.Here's some info that might helpt:---------------------------------------------------------------------------------------------------Recommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

Princeton University’s Eviction Lab estimates 1.5 million Americans face eviction annually.

Just focusing on reducing debt , I tutor chemistry which has been helping with finances.

@Jay Hinrichs are you sending that soil sample off to a lab for testing?

She's has an enormous dog (lab) at the house so I didn't attempt to go there to post the notice on her door as he had bit someone before.