Pond Boss Forums GENERAL QUESTIONS Water chemistry That Blue stuff

There are numerous blue dye colorants now on the market; they are basically non-toxic food type stains or dyes with an emulsifier. Aquashade, Crystal Blue, Blue and Blue/Black Vail, Admiral Liquid, and the list goes on. Only two are EPA aproved as a weed/algae controlling agents = Aquashade and Admiral Liquid. Aquashade is now made and sold by Applied Biochemists in Milwaukee WI.

They work by filtering out the red and orange wave lengths out of water deeper than two feet. This assumes you use the proper or labeled recomended dosage. They are designed to stop or dramatically supress most all of the green plant growth in water deeper than two to three feet. Suppresion of the plant growth also cause a big decrease in the production of dissolved oxygen in the water column. Too much suppression of oxygen production in the depths can also cause low DO and fish kills esp during rainy-cloudy periods. I see this most frequently in early spring when stratification has not stablized.

There are several blue-green algae types that that do not rely on the red & orange wave lengths for growth. So these nuisance & resistant algae species persist or thrive in the presence of the blue dyes.

Plant reduction from blue dyes also includes the beneficial phytoplankton (most are green algae & diatom types) which are the base of the fish food chain. Severe reductions of the phytoplankton/periphyton communities cause large decreases in each of the upper food trophic levels in the pond; this includes all fish biomass. I usually tell pondowners that when used according to the labeled instructions blue dye will cut the fish population by approximately 50%. Blue dyes are designedd to stiffle plant production and they work for most aquatic plants.

Blue dyes are used extensively in my area. This is the only way that most novices know as the easiest, benign way to keep pond plants minimized. In ponds that use blue dyes the only ones that have "decent" fish populations are those where the fish are fed pellets. Pellets make up or suppliment the lack of natural production of fish foods.