We notified the existing tenants of the change in ownership, and informed them of the rent increase, about $65, starting 2 months out, stating it was fair market rent, which was true  We stated we would make improvements to their Units, like above, with the exception of painting and refinishing of cabinets (too invasive for an occupied Unit), as well as repair any issues, like slow drains, which was found during the building inspection.

But I can think of way more annoyances of cleaning the pool, draining the pool, chasing mice out of the empty pool, etc.

I know states like Indiana are closer to .11 or something.I should also add that people should look for huge electrical drain and upgrade those appliances if their goal is to save money.  

Wherever it slopes, there will be significant water flowing, and if that water isn't managed correctly, it will cause problems (even if it is managed correctly, it can cause problems--because you, or someone, has to manage the water management infrastructure to keep it operational).If the driveway does slope toward the house, the accumulating water can cause foundation settling, masonry degradation, rot, possibly flooding, etc.Water is the enemy of houses--and understanding the specifics of how water moves, accumulates, drains, etc. is probably the most underrated skill in real estate investing, IMO.Good luck out there!  

I also though about extending my roof a bit.BTW, I do know about other solutions such as...fixing the grade, underground waterproofing, interior drains, weep holes, dehumidifiers, etc.

They claim they wash dishes in a bucket (we see the bucket) and don't throw any food scrap or other trash down the drain.

Your parents & retirees who are taking SS are taking water out of the bathtub (the drain). 

Anything relating to shower/tub drains not functioning properly, issues with washer hookups, leaks of all sorts, etc., having this role be a text away is a must!

To decrease your learning    curve a local mentor who does not drain your wallet is a good option.2) Your mailings were not targeted enough.

Another option for laundry is to run plumbing upstairs, tap into a drain line, and add a small stackable somewhere if there is room.