[hsuesmpf] Controlled biological carbon sequestration

We are wary of iron fertilization of open ocean because it may have unintended consequences worse than the global warming it is trying to fix.

Can we do something similar but in a controlled environment instead of open ocean?  Perhaps divert a river into a large artificial pond.

Consider using the aquatic plant Azolla instead of phytoplankton: Azolla has been paleontologically proven to be able to reduce global warming.  There remains the problem of where to put the harvested Azolla where its decay will not immediately return carbon back into the atmosphere.  Perhaps deep mines, or Antarctica.