Ok. Seen your recent post indicating 7.8 It'll probably take that whole jug to get somewhat near 7.2 The acid you have is supposed to fume less and be somewhat safer than regular muriatic acid.
Regardless, there's safety precautions that should be taken into account with both kinds. I don't mix mine with water in a bucket but some folks do. In that case you always add acid to water and never water to acid. For instance: You put a couple gallons of water in a bucket and add your recommended amount of acid to the bucket of water.
You want to be upwind so any fumes are blowing away from you and not towards you. Some people wear safety glasses and rubber gloves. If you want to be technical, safety glasses are a poor substitute for goggles and a face shield.
Ok, now that I've probably frightened you it's time to relax.
Take that jug and hold it front of the return in the water. Push it down so the cap is a couple inches above the water. Uncap it, and slowly tilt the jug so it pours and only has to go a half inch or so to hit the water with no splashing. Remember this is in front of the return so the water is pushing it out into the pool.
Guestimate and pour a little more than half into the pool. Recap and let your pool water mix for 30 minutes and retest. I would say it's going to take the whole jug but I've never used the so called safer stuff. But it's good to get in the habit of proper handling and under dosing to avoid problems of over shooting.
Oh yeah forgot to add that when you take the cap off dunk it under water to rinse any acid clinging to the cap. I had a few spots on my old ABG pool from putting the cap on the rail upside down.