The water connects the electrodes to your skin and ensures that the current can flow. It also protects your skin: if there is too little or no water between your skin and the electrode, this can lead to electrical irritation or minor chemical burns.
What you should bear in mind:
Your skin should always be well moistened with water. If using sponge pads or fabric electrodes, these must remain well moistened throughout the treatment.
Normal tap water is sufficient. Only in the case of extremely soft water may conductivity be reduced – in which case, ordinary bottled water can be used as an alternative.
Additives such as salt or other substances are not necessary and may even promote side effects.
Tips for more comfortable and safer treatment:
Use warm water. It opens the skin pores, reduces resistance and feels more comfortable.
For hygiene reasons, the water should always be changed between applications.