Should I give reason for ending tenancy?

[Walter C.]

I decided to end the tenancy of one of the tenants. I have told him repeatedly, and thought he was actually doing it. But it turned out, it was his roommate (who moved in without telling me, but turned out to be a good tenant) that was doing the cleaning up. And now, that roommate will be moving out soon, and has told me that the main tenant was not cleaning up after himself. That was when I had enough, and decided to end the lease.

He has been living month-to-month for some time now. This is the first time I have done something like this, where it was for other reasons besides not paying rent. I have sent him a letter that he has to move out in 60 days, but did not give reasons why I decided this. Was I suppose to do that, telling why he has to move out?

I feel bad doing this, but I always have to remind myself that I am not a charity.