so i jus tried calibrating my oakton ph meter please tell me if done right. i turned it on pressed cal and placed it in 7.0 solution and pressed hold ent. afta that i rinsed probe off in distilled water then placed ph meter in 4.0 solution and pressed hold ent. rinsed probe in distilled then i tested distilled water ph came out at 5.7 i also tested my tap water ph 6.6 did i calibrate my meter right please any help would be greatly appriciated