In order for mold to grow, water and/or moisture must be present.

I'm the owner and no maintenance man or PM will ever do as good of a job as me (unless of course you're talking about gas appliances, electrical and permitted plumbing work- all a different story)If it were my property here is how I would prioritize: A bathroom vent fan that doesn't work, -all moisture should be dealt with accordingly, fix it first.Also, they broke the skylight lens when attempting to clean it...

I like some of Beth's theme of things that do double duty (like new door mats and bath mats, which are dual purpose gifts that also protect your property from grit and moisture!).

We also have tenants sign off on this form:DISCLOSURE OF INFORMATION ON MOLD AND MOISTURE HAZARDS(Addendum to Rental Agreement)The Rental Agreement dated _________ between ____________________________ (Landlord) and _____________________________________________ (Tenant), of real property located at __________________________________________________, is hereby amended in include the following terms and conditions: “Disclosure of Information on Mold and Moisture Hazards.”

Mold needs moisture and deferred repairs for water issues will make the problem much worse.

Try to get a free inspection from mold assessors, structure companies, crawl space encapsulators, etc. paying particular attention to the wood moisture content under there.

The unit has also been tested for environmental issues and moisture was below "dry levels" and indoor air quality levels were okay though CO2 levels were just above guidelines in some rooms.The tenant is known to use a lot of candles, we're wondering if this could cause this.Does anyone have any ideas?

That'll alleviate the moisture issue.

They find that the water on the ceiling was either due to the moisture/humidity from taking a shower or from just water splashing.  

Many landlords don't do what is necessary to mitigate the risk of mold and moisture in the home.