more like, 1/8 gallon. Don't try to measure it -- doing so will create too many fumes. Instead, eyeball it. With a pH of 8+ and TA of 170, 1/8 gallons, give or take, will not be too much for a 7,000 gallon pool.

Partially immerse the jug in the water, and then pour with the lip of the jug only a inch or so from the water. Doing minimizes the fumes. Only add acid when the pump is running, and wait 4 hours before retesting pH.