Mack-Cali Realty Corp., a real-estate company in Edison, announced on March 21 it paid about $262.5 million for Crystal House, an 828-unit apartment complex in Crystal City, Va., from luxury apartment developer AvalonBay Communities of Arlington, Va.

Cantel Acquires Siemen’s Division

Cantel Medical, an infection-control product distributor in Little Falls, annnounced on March 26 that its water filtration subsidiary, Mar Cor Purification of Skippack, Pa., acquired the hemodialysis water unit of health-care manufacturer Siemens in Munich, Germany.

Online Tutoring Company Acquired