A 13-step protocol detailing the proper procedure for changing media in kelp gametophyte cultures. Outlines essential supplies, sterile technique requirements, and precise media preparation using F/2 and pasteurized seawater. Includes guidance on culture inspection, water exchange techniques to preserve gametophytes, and proper documentation practices. Features specific instructions for handling potential contamination and maintaining biosecurity standards. Essential reference for nursery technicians maintaining kelp gametophyte cultures to ensure continued viability and health.