I'd like to do a WOW style thing with more colour and body, and I'm wondering about upping the fruit juice content and dropping the sugar accordingly. Any reason not to use, for instance, 2l Welch's PGJ, and 2 litres Blueberry Juice drink (with no weird preservatives), just topped up with water, and the sugar reduced in line. I realize this would be a little more expensive, but I can't see why it wouldn't work.