Eric Woollard, 28, of Des Moines, remains at Mercy Medical Center.
Rescue crews were called to Chemorse at 1596 Northeast 58th Ave. just after 1 p.m.
Saylor and Ankeny fire units were dispatched to the scene.
Workers told rescue crews that Woollard was near the tank when he suddenly disappeared and they noticed the liquid in the tank moving.
Several workers lowered a strap into the tank and pulled the man out.
Woollard was alert and conscious when he was taken away in an ambulance after going through a decontamination process.
Authorities said the tank contained a cleaning solution.