Fixed leaking connection on undersink RO system. Found crack in housing of second stage filter. Replaced housing unit and all O-rings while on site. Also noticed flow restrictor was partially clogged - cleaned thoroughly. System now operating properly with no leaks. Performed complete sanitization while system was disassembled. Checked TDS levels before and after repair - system now reducing TDS by 97%. Recommended replacing all filters since they were nearing end of service life anyway. Quick 1-hour job, all cleaned up!