Types of Growth Systems

Raceway ponds can be constructed in a variety of ways. For wall supports, either earthen berms, which are made by moving around and compacting the earth with construction equipment (Lundquist et al., 2010), or concrete walls and floors can be implemented 

Closed systems also control contamination much better than open ones (Mata et al., 2010). However, there are some solutions to controlling contamination in open systems, like choosing a resilient algal species, hi addition, extremophiles can survive in environments that most others cannot. For instance, culturing Spirulina at high pH values from 9 to 11.5 and D. salina in hypersaline conditions reduces the amount of grazers and other species that could harm the system (Schenk et al., 2008 Lundquist et al., 2010). 

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