Doing my first full panel in a while and when I went to the new Recommended Levels interactive page ( What Are My Ideal Pool Levels? - Trouble Free Pool ) I saw the CH figures are recommending 350-550. Normally I pick a middle point so I would need to bring my CH up to 450. Have I not been paying attention or has it always been this high? Thats 302 oz (280->450, 15,000gals) that I need to go mix in today.