Algae ponds require plenty of sunlight along with vital nutrients to flourish. As to sunlight needs, most all algae rely on photosynthesis to produce food for themselves—and that means they require lots of bright light. While the amount varies from one species to another, most will require a minimum of four to eight hours of bright direct sunlight daily or the equivalent of that if you’re using artificial light sources. Bear in mind that producing high-lumen artificial light can be costly, so plan ponds with plenty of natural sunlight exposure wherever possible.
Next comes the nutrients. You’ll need a soluble fertilizer for most types of algae—though chlorolla is one of few types that won’t require much, if any fertilizer. These fertilizers will need to contain nitrogen and phosphorus to support rapid growth. Minerals are another crucial part of your feeding system. Sometimes, naturally hard water can fill the mineral requirement, but in areas with soft water, you may need to supplement. In salt or high salinity algae ponds, you’ll also need to add salt, dissolved calcium, and other ocean minerals to keep algae thriving. In dark systems where the algae doesn’t require sunlight, you will likely need to feed your algae with glucose. In the absence of photosynthesis, glucose becomes the source of carbon that algae uses to produce its own food. Typically, this requires a special type of algae—though some of these algae varieties are among the fastest growing available, with a high commercial potential. High amounts of carbon dioxide will also be necessary. All plants, including algae, draw in carbon dioxide and release oxygen as part of the food production process. Without CO2, algae will grow slowly or even experience a die-off. In some systems, gas spargers are used to force carbon dioxide bubbles throughout the pond.
