He said I need to be patient and that he can't do anything until I see visible signs of what's there and it would be hard for him to pin point anything since the apartment was recently renovated and the only problem right now is a strong musty/ mildewy smell.I am going to get a highly recommended HEPA air purifier so the tenant isn't breathting this stuff in. https://www.alencorp.com/products/alen-breathesmar...I'll also call more moisture companies.

Purchase an Air Purifier for their son's room and main living area.  2.

They will need to treat airborne with ozone and air purifiers. 

We run an air purifier in our daughter’s bedroom.

I also do not mind doing this work as it is good learning experience for the future invetment propertiesHere is the scope of work I am considering to move the rents from 925 to 12-1300. 1.the paint is only in the living room as there is a bit of a smokey smell now so I am going to hit that with Shellac primer, and air purifying paint ($350 + my time)2.

I had also spoken to the neighbor who smokes in the below unit and bought an air purifier before moving out - I had noticed clear improvement and the neighbor seemed to be smoking less.  

Most people on public water in the US are getting a gallon of water, delivered, purified and pressurized, on demand at their faucet any time day or night for less than a penny.

I just purchased a air purifying machine and plan on leaving it running for a few days.

I bleached the walls and put an air purifier running 24/7.

i even purchased two $150 air purifiers and gave him a third to be placed throughout the home to help with air quality.