Microscopic hematuria can be due to
urinary tract (bladder)
infection, swelling in the filtering system of the kidneys ,stone in bladder or in a kidney, blood disease, like sickle cell anemia, certain medicines and tumors in the urinary tract.
I suggest you to consult a urologist for your father and get done an ultrasound abdomen to look for any kidney stone and blood tests for sickle cell anemia.
I hope it helps. Take care and please do keep us posted on how you are doing. Kind regards.