Just as electronic technologies have improved with time, technologies in the water distribution system have evolved from large and expensive pieces of equipment into smaller and more efficient solutions. Developed in the ‘80s, passive mixing systems use bulky nozzles with one-way valves to squirt water in different directions during the fill cycle. Because these mixers rely on the momentum of influent water, passive systems do not mix water once the tank is full or during the drain cycle and tanks re-stratify once the infill has stopped. A common workaround is forcing tank operators into a minimum turnover rate (which is both energy-intensive and expensive).