Last summer (2018), Confer Plastics made product improvements to all of its products that involved filling in any openings beneath the water line. The improvements were put in place to prevent entrapment. This included the sidewalls on the curve step system. To prevent any algae build up, at least once a week, and while inside swimming pool, use a garden hose with a high pressure nozzle to spray under and behind the curve step system. The water force will flush out any dirt and circulate it into the pool filtration system.