Moral dilemma on raising rent

[Nat C.]

I'm in a crux about what to do on 2 rentals. I've never raised the rent on both properties since the tenants moved in. One tenant has been there 5 years and the other nearly 7 years.

I would like to start with a prelude that money is not what drives me in life and ethics is the most important thing to me.

Neither house has a property manager and both tenants deposit the rent into my account each month, on time, without fail. I bought these houses when the market was at the bottom, so my initial investment was low. The tenants have already well and truly paid off what I bought them for.

House 1 Orlando: 3 bedroom house. Tenant pays $720. Rent comps are now $900-$950. He is a single guy, has children and from what I know, he looks after the house like it's his own home. He has been there nearly 7 years. Generally if something need repairs, he will fix it himself. If he needs to buy a part from the hardware he will send me the receipt and I tell him to deduct it from the rent. Total maintenance cost has therefor been around $100 since he moved in.

House 2 Phoenix: 3 bedroom house. Tenant pays $870. Rent comps are $1100. The tenant is an elderly lady and has been there around 5 years. They only contact me for necessary repairs and total maintenance cost has been under $500 in 5 years.

I was thinking of asking both tenants if they would agree to a reasonable rent rise of around $80 a month. If either of them say they can't afford it then I will not push ahead with it.

Has anyone else been in this situation? What did you do and how did the tenant respond?

Please don't respond saying I'm a weak landlord who should jack the price up to market rent. Good tenants should be rewarded and I'm not in dire need of a few extra dollars.