New landlord questions

[Michael Junior]

Two questions 1. Am I able to split the water bill with tenant in the duplex I currently live in ( and own). I recently just understood that your supposed to include all expenses into the tenants rent. I just picks up my first duplex. I’m house hacking. I have inherited tenants that are paying $1500 a month. When I sat down and signed the lease with my tenants we agreed to keep the rent at $1500 but i asked they split the water bill with me. Is this acceptable??