I'm not a pro, but I've poured a whole gallon in our pool before and swam the next day. I turned the pump off for 20 minutes, poured the acid in at six different spots around the edge, left the pump off for an hour, then I turned it on and let it run all night. I've heard people refer to it as "slugging". I'd wait and see if any night owls reply to post. But, I've done it, 14600 gallon AG pool, and it didn't do anything bad that I can tell.