During a session, the water will change colors and develop particles and or foam.
These changes are the result of the electrolysis process and the interaction between the array, the salt water, and the individual user.
Different conditions and the individual user can affect what you will see in the tub.
The appearance of the water is not a direct measurement of toxins in the body. Photos below demonstrate progress of foot bath from water color first changing to foam and particles forming. Consult color chart for potential indicators.

Start of session
During session
End of session