My response to Shahriar was not necessary and a bit harsh.

Hello,My name is Elyse and I am currently pursuing my undergraduate degree in Chemical Engineering  at The University of Arizona.

@Michael Jone  I hear what your saying many on BP will say the same thing don't spend money on training you can get it all here at BP  although @Russell Brazil comments are in my mind made in a manner that in genuine .. so I think you were a little harsh on himThe reality as @Aaron Mazzrillo stated is these companies are all fronted by UTAH based seminar companies Every single one of them..

I work in a chemical plant so the stuff I work with isn't really the best for me either.

Speaking of costs, if I did have a rental with a pool, I would factor in the cost of you (the landlord) providing/paying for the regular maintenance and chemical treatment because tenants aren't likely to do it (at least not properly). 

If he has been living in the house for 20+ years and is a moderate to heavy smoker, there may be rooms where scrubbing, sealing and painting simply won't keep the chemicals from coming to the surface and you will end-up pulling down the drywall and hanging new.We renovated a house some years ago where the former owner had a favourite chair in one corner of the living room where she sat and smoked.  

Welcome to BP @Harsh Thakker. 

Last suggestion is to find a couple chemical suppliers in the area and talk with the chemical reps.

I don't mean to be harsh or condescending.

I wish that money did not have to be a concern, but the harsh reality is that it is a major concern.