The marked advantage of these open ponds is their simplicity, resulting in low production costs and low operating costs. Operation is very simple for this system, which only has a giant rotating mixer at the center of the pond to avoid the precipitation of algal biomass. Although this is indeed the simplest among all the microalgae cultivation techniques, it has a major drawback: The environment in and around the ponds is not completely under control. Bad weather conditions can stunt algae growth due to the lack of environment control. For example, high temperatures as well as insufficient or excessive sunlight intensities are critical factors affecting the efficiency of microalgae growth (Norsker et al., 2011). In addition, con­tamination from bacteria or other foreign microorganisms often results in the predominance of undesirable species over the desired algae growing in the pond. Rainy conditions are also a common contamination source, since the rain may flush down enormous microorganisms into the ponds from the air. Therefore, finding an appropriate cultivation location is crucial to the success of such open systems. Even though there could be many disadvantages with the simple pond system, the simple operation and the high scale-up availability of simple ponds are still very attractive factors and these ponds are often utilized for industrial production of microalgae (Borowitzk, 1999).