DR prescribed Monopril 5mg, HCTZ (hydrochlorothiazide) 12.5mg & KLOR-CON 4mg for mild, longtime HTN. My potassium levels are normal. Is KLOR-CON necessary or risky?

Probably not. Any excess potassium would be eliminated in your urine, as long as your kidney function is normal. HCTZ (hydrochlorothiazide) is a diuretic, and your doctor wanted to make sure that you would not develop low K, which is dangerous.