Quick & Easy Test Strips for FROG @ease with SmartChlor The FROG @ease Sanitizing System for Swim Spas, the first and only System of its kind, naturally uses unique test strips. FROG @ease Test Strips let you know when your SmartChlor Cartridge is empty. You won't have to bother with chlorine level measurements because it self-regulates at a consistent level every time. Instead, the single color on the bottle tells you whether your cartridge is in good condition or if it's time for a replacement. In 2 seconds, you can know precisely whether your pH, Total Alkalinity and Total Hardness are balanced, plus whether or not SmartChlor needs replacing. Simply dip the FROG @ease Test Strip into the water, remove with the pads facing up and shake once to remove the water on the FROG Test Strips. Then hold it up next to the color chart on the back of the bottle to compare colors.