President Trump announced in a press conference Thursday that chloroquine phosphate -- a substance found in drugs used to treat malaria and severe arthritis -- was cleared by the Food and Drug Administration (FDA) to test as a treatment for the coronavirus. That same substance, outside its pharmaceutical form, is used as an additive in aquariums to kill microscopic organisms that might harm fish and other aquatic animals. And, the prices for chloroquine phosphate have surged online in late February and early March, according to a study published Thursday, sparking fears that people may be ingesting the fish-tank additive in...