How much smoking proof is needed to non-renew

[Jared Miller]

I purchased a duplex that came with tenants. Tenants I probably wouldn’t have approved. The neighbor is complaining of cigarette smoke coming thru the air ducts. I was just there to look At their fridge and found a cigarette butt under the fridge and didn’t say anything. How much proof of smoking do I need to say this is their last month and I will not renew their month to month lease? 

[Ryan B.]

You don't need any proof.  You don't need a reason for not renewing a month to month lease.  Just give them notice.