The order of the Judge of Industrial Claims is affirmed except insofar as it allows the carrier to take a retroactive social security off-set. The carrier is entitled to the off-set only as of August 18, 1978, the date it first exercised its right under Section 440.15(10), Florida Statutes (1977). Pensacola Buggy Works v. Jernigan, 377 So.2d 245 (Fla. 1st DCA 1979).