This is a 300 ml starter culture of live green water. I’m using “green water” as an umbrella term for a living culture primarily consisting of multiple species of single cell algae and other infusoria. This culture is best used for starting your own larger green water culture. This is a live green water starter culture that is perishable. It's best to start your green water culture soon after receiving your starter culture. Click Here to see the Green Water Machine instruction manual. This may help you understand what is involved in making your own green water.