This board is great for laughs. We have no idea exactly what strain of algae is being grown (there are over 30k species that have been discovered by science), and what the optimal temperature ranges are for said strains. Some strains (such as blue algae) thrive in hot environments that no other life on the planet would be able to survive in.
BEHL is growing basic plant matter, something that grows naturally EVERYWHERE that water exists. And btw, even if a particular strain is better suited to grow in cold water, it can be bio-engineered to thrive just as well in warm water.