The terms alkalinity and hardness are often used interchangeably when discussing water quality. These aggregate properties of water share some similarities but are distinctly different. This 7-page fact sheet describes alkalinity and hardness, their importance from management and ecological perspectives, methods for measuring each, and the current state regulations for each in public waters of Florida. Written by P. Chris Wilson and published by the UF Department of Soil and Water Science, October 2010.
http://edis.ifas.ufl.edu/ss540