 Their first successful product was a simplified titration method for measuring hardness in drinking water, which they packaged in easy-to-use testing kits.As municipal standards for drinking water were developed, Kitty recognized both the importance of water plant operators as a market, and the need to work closely with them to develop standards and provide long-term customer service.She developed a direct mail marketing campaign, and earned the nickname "Kitty" Hach by flying her plane across the United States, sometimes landing on rural dirt airstrips in bad weather, delivering water quality testing kits to municipalities of all sizes.