I wouldn't call an FC of 18 way too much bleach. it's in the shock range for 45 CYA - where you want to be with a hint of green and measurable CC.

You probably read about using borax to add borates to the water. This requires Acid to reduce the pH as Borax raises it. Borax is a very good way to raise pH without affecting TA (much). Washing Soda may be a better choice for you as it raises pH and TA. Washing Soda - Arm and Hammer Yellow box in laundry aisle is not Balking Soda in the orange box. Baking Soda will raise TA with less increase in pH. Aerating the pool will have less effect on pH when the TA is low.