I bought a duplex and cut my living expenses to ZERO. How to keep a long term tenant?

[Irving Casas]

In 2020 after months of listening to BiggerPockets and analyzing deals. I focused on buying a duplex in Portland, Oregon.  On February 8th, 2021 I bought a duplex for $388,000. The tenants who were on a yearlong lease were paying $1,300.  I work as a realtor and night shift at a hospital as a respiratory therapist, I don't have my own family. Once I moved into the vacant side of the duplex, I realized I still only needed a room to sleep. I had reversed house hacked my entire adult life to save for my downpayment.  I rented the vacant room for $725.  My mortgage is $1750. My expenses include taxes, home insurance, water/sewer, 5% for vacancy and 10% for capital expenditures and maintenance. I can now save my entire paycheck and commission checks to save for the purchase of my next investment property. Even though I work quite a bit, I still find time for yoga in my backyard, snowboarding 1 hour away from my home, I'm 15 minutes from 3 beautiful rivers and 1.5 hours from the Oregon coast. Portland is a wonderful place to live. 

My tenants have lived in the duplex for 20 years and they are great. They treat the duplex as if it was their own home. 
Bigger pockets community, what advice do you have to keep a long-term tenant happy?