Arnold was the brother of Roy Potts. His parents were the Rev. George Potts and Mrs Ada Elizabeth Potts, of Irvine St, Peppermint Grove. In about 1914 he sailed to the UK to further his religious studies and joined the British military as a soldier or chaplain and was killed in France. In 1914 Arnold had been engaged to Miss Lucy Harriet Saw who later trained as a nurse and served the Rockingham community for many years. She never married.