At 20 Liters, we’re committed to making dirty water clean. How do we do that? Through Slow-Sand Water Filters and Rainwater Harvesting Systems. These simple and cost-effective solutions work to both reduce the difficulty in accessing water, as well as remove the harmful bacteria from water that’s been collected from contaminated sources, such a river or a pond. The end result? Improved health, as well as an improved quality of life.