Please review my Deposit refund letter - Charges due! - PA

[Shannon Trivett]

Tenant moved in July 15, 2015 with a one year lease. Tenant informed me in June of 2016 they would need to move in January 2017 so I didn't do renewal paperwork. I was sloppy on the initiall lease and and missed the renewal check boxes on the lease.  Shown below:

Tenants have since sought divorce and have vacated. Last rent payment was made on 7/15/16 paying thru 8/15/16
I was notified on 9-2-16 that I should use the sec. deposit for the 8/15/16 - 9/15/16 rent and they would be out by 9/15/16

I sub-meter the water via Guardian. 

below is the letter I would like to send to the former tenants. Can anyone tell me for sure if I'm able to charge a month's loss due to improper notice?

Would you change the way anything is stated?

i will attached the water bill and some photos of crayons, wall paper damage and general dirty-ness to the hard-copies I mail the tenants. I could also post here if anyone is curios.