O’Neil, Swan and Anderson continue with the Sand Superman saga in issue 237 (May 1971).
After a mission in space, Superman finds that his costume has become infected, and any life form it comes into contact with expands. But it takes him a while to figure out what is going on, and matters are complicated by the Sand Superman, which continues to hang around, draining him.
Lois Lane is on an assignment gone bad in Central America. Superman flies down to help her, and it is when the ants that climb on him turn monstrous that he figures out the costume problem. But what to do about it?
His brief contact earlier with the Sand Superman seemed to sterilize part of his uniform, so he flies full tilt into the creature, and it works.
Superman does get around to rescuing Lois, but seems much crankier about it than usual.
The Sand Superman finally talks at the end of this story. He has been draining Superman, and the two are almost equal in power now.