How about training the tenant:"Medical marijuana may only be smoked in this room (bathroom) while the exhaust fan is running.

Without owning real estate investment my W-2 effective tax rate would be near the tax bracket.Notes have little expenses so no exhaustive list of write-offs. 

(landlord to do it)Take out the filter, wash it with soap, wipe it dry and put it backChange the heater filter (landlord to do it)Check exhaust from the dryer.

Proper venting of bathroom exhaust fans is very important.

@Micheal Johnson You may purchase an umbrella policy, which kicks in after you have exhausted your Homeowners liability limits.

Its exhausting…..6.

Reed gave an exhaustive analysis on "Due Upon Sale."

Are there any other methods out there that I have not exhausted?

That policy will provide additional coverage (usually sold in increments of $1,000,000) that is triggered if the limits of underlying Personal Auto, Home, and/or Dwelling Fire policy are exhausted. 

Humidity can be caused by humidifiers, not running the exhaust fan when showering or even occupants of the space can create humidity.