Blue/Black Vail

Like Blue Vail, they contain no herbicides or algaecides, are nontoxic and safe for fish, humans and birds. The quarts per acre are typical for 3 acre-feet or approximately 1,000,000 gallons. Sold in quart bottles.lean, clear water in a lake with a natural black bottom looks black from all angles. Blue/Black Vail (a 50/50 mix) and Black Vail concentrates give you one of the most natural looks on the market. They are used in some of the finest lakes and garden ponds in the USA. Not recommended for use with fountains.