Should I raise the rent on current tenant?

[Zackary Martin]

I’m buying a duplex. One side is currently rented to a couple that’s lived there for the past seven years. They’re ideal tenants who look after the place like it’s their own. However in the time that they’ve lived there their rent has never been raised. They’re currently renting it for $750 and they pay their own utilities. The unit could easily rent for 1,000-1,100. I don’t want to lose them but I also don’t want to miss out on that much potential rent. What should I do?