The most common use of pond dyes is to retard weed and algae growth, since all pond dyes are food grade, they can be used safely with no restrictions on water use or harm to anything living in the aquatic environment. Pond dye retards weed and algae growth by cutting down on the sunlight penetration into the water, usually if a pond is dyed correctly, you will only see about 2 - 3 feet down into the water, so that all weed and algae growth will only be found in the extremely shallow areas. Pond dye also can improve the appearance of your water giving it a very natural blue tint, it should be pointed out however that the pond dye will react with what ever color is in the pond, if your pond looks yellow adding blue dye will result in a green coloration not blue.
Aquatic Systems carries the following brands of Pond Dye.
AquaShade - Aquashadow
Aquatic Blue Dye
Aquashade and Aquatic Blue Dye are liquids and need to be sprayed around the pond or lake, Aquashadow comes in a water soluble package and the packages are just tossed into the pond or lake, the package dissolves and the powered dye has it's own dispersant that spreads around the pond quickly.
If you are using either the liquid or the packages it is a good idea to apply the dye at a calm period during the day, a slight breeze when you are spraying the liquid can turn you into an instant smurf (little blue people), since the packaged dye floats till it dissolves a breeze can shove the packages to the shoreline where it will take longer to spread around the body of water. If you do get some of the dye on your skin or clothing it can be easily removed with a little bleach or anything that contains some chlorine or ammonia.
Pond dye works best in ponds with good water clarity and only retards weeds and algae that are growing at the bottom of the pond, a good rule of thumb is that pond dyes will not affect any weeds and algae that are already in existence, but will retard new growth. Pond dye has no effect on weeds that float on top the water or that are sticking out of the water like Cattails. Pond dye can be used year round, and a normal treatment of pond dye will generally last 2 - 3 months in a contained pond or lake. How long the dye will last for you will depend on how much flow you have going in and out of the pond. Pond dye is neutralized by chlorine so it has no application in swimming pools or swimming ponds that use chlorine or bromine.
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