Connor Michael Kasubowski was visiting the farm in Alcona County's Gustin Township on Sunday with his mother when he was reported missing. The boy hadn't been seen for about an hour when deputies arrived at the farm, and one of his shoes was found near the tank.
Crews pulled Connor from the tank and he was pronounced dead at a hospital.
"Our investigation is indicating there doesn't appear to be any wrongdoing," Sheriff Doug Atchison said.
The investigation is ongoing.