Pond Logic, Pond Shade: Blue Sapphire (16 Oz.), 130130
Product Review (submitted on July 13, 2013):
I looked everywhere for something to add to my fountain that probably holds 3 gallons of water on three tiers. This is the first I found that didn't come by the gallon and cost $30 - $40. We put a few drops in 3 or 4 weeks ago, and even with the rain and adding water, it's still a beautiful blue. Not sure how it is in actual pond, but I'm sure it would be great in any small yard feature.