Upstream Black is a concentrated easy to use aquatic colourant. Natural dyes darken the water and preclude sunlight from promoting re-growth of algae and weeds whilst giving a much improved aesthetic appearance. Applied at the surface, it rapidly disperses downwards to provide a natural black colour within minutes.
 
Upstream Black is a liquid formulation that allows flexible application rate. It slows algae growth and is designed for effective use with Upstream BioClear. Upstream Black should be used after Upstream BioClear has removed algae and 1 lt will cover approximately 2,000m³. Upstream Black should be used between May and October.