Making large amounts of acidified water
I'm gonna have a lot of blueberry plants to water and often. I don't have a rain water cache system so will be using city water which has a pH of 6.5. I was thinking that it would save me some time if I mixed up a large batch of acidified water at a time in say a rain barrel or regular trash can with lid and then use it to repeatedly fill up my watering can. Then maybe I only need to make a new batch once a week (or month?)
Good idea, bad idea, got a better idea?