Algae: Small plant life which rarely grows in spa water. Often green, yellow or black, algae is slimy in texture.
Alkalinity: How alkaline is measured in spa water, i.e. above 7.0 pH.
Alum: Aluminum sulfate, commonly called floc, is used to help clarify water.
Calcium Chloride: Added to raise calcium hardness.
Calcium Hardness: A measure of the level of [...]