The pool was refilled on Tuesday. The water is Chicago tap that's gone through a carbon filter. On Tuesday the salt was added to get it up to the proper salinity.
"These animals came from the ocean so our goal is to try and replicate the environment and make an ocean here in Chicago. These animals require the salt for buoyancy and for their skin," said Allen LaPointe, Shedd Aquarium.
The Sea Mammal Pavilion is set to re-open Memorial Day weekend.