** Shares of Calix CXL.AX rise 6.6% to A$0.2825

** Stock set for its strongest session since March 25

** Environmental tech co says its water treatment products sold in the U.S. are exempt from tariffs

** Co expects to record continued 2H FY25 revenue growth in its magnesia business, which accounts for 79% of its revenue

** 42,479 shares change hands, 3.1x the 30-day average of 13,538 shares

** Stock down 62.3% YTD, including current session's moves

(Reporting by Manasi Dasa in Bengaluru)

((Manasi.DasaSundeep@thomsonreuters.com))