Surprisingly, depth doesn’t necessarily mean that you’ll produce more algae—shallow ponds are often preferable. In a fish pond or pond devoted to growing certain types of plants, you may need specific depths in order for your aquaculture products to thrive. Algae, however, typically thrives best within the first few inches of depth. That’s because this is where light is most abundant, and it’s where the carbon dioxide exchange rate is the highest.
Thus, most algae ponds suitable for microalgae range between anything as shallow as two inches deep to a maximum of 40 inches. Seaweeds and macroalgae are a bit different and may require ponds that are a few feet deep, but microalgae varieties will almost always grow more rapidly in shallow ponds. An additional advantage to shallow depths, aside from light penetration and carbon dioxide exchange, is that they’re easier to mix, which provides vital mobility so that all of the algae in the pond can circulate to the surface for sunlight.
