which is better tax deduction for water bill or tenant paid water

[Jesse Poll]

I sent a link to a friend about sub metering their water after a conversation where they were complaining about tenant water usage. Her response to me was I don't know how this could help me because the water expense is tax deductible. After more research I found out that each unit already has it's own meter and is billed to the owner. This could be billed to the tenant.  Am I wrong in thinking that passing this cost to the tenants would increase net income and ultimately the value of the property more than the tax deduction of the water expense paid by the owner? I am trying to get a better understanding of this.