In most decorative ponds, the pond water gradually turns greenish. It is hard to peer deeply into the dingy water. Many fountains and ponds in public parks use blue dyes to increase visibility through dingy water and improve the appearance of the pond, but these specialty dyes can be expensive. If you want to add a bright shade of blue to your water, or if you want to add a nontraditional color to the pond, you can use basic food coloring to make your own pond dye.
Fill a 1-gallon bucket with water from your pond.
Pour 1 tablespoon of food coloring into the bucket. Blue food coloring is traditionally used, but you can add other colors as desired.
Stir the mixture with a spoon or stick.
Add additional tablespoons of food coloring until the water is adequately colored for your purposes. The more coloring you add, the darker the color will appear in the water.
Pour food coloring into your pond based on your mixing ratio from the 1-gallon bucket. For example, if you have a 125-gallon pond, and you want to add 2 tablespoons of color per gallon, then you'd need approximately 1 gallon (256 tablespoons) of food coloring.