I don't think you can drink ditch water Chris. Prove it and document it.
Lots of folks have used this method with great results along with other homemade recipes. I also agree with Ben that human consumption has far more stringent regulations. For me it comes down to simplicity and buying reef ready items is far easier.
Plus, all I saw opinion that pic was the watermelon on the bag. I miss some pickled watermelon rind.
John
"Critics are men who watch a battle from a high place and then come down and shoot the survivors." Ernest Hemingway