Interacoustics Aqua Stim Instructions For Use Manual page 13

Aqua Stim Water Irrigator Instructions for Use - US Page 9
You should always use fresh water in the external tank. Tap water may be used in
the Aqua Stim provided that the water is not "hard water" due to excess mineral
content. Build up and / or damage from mineral deposits is not covered under
warranty. Demineralized or distilled water is always recommended and should be
used if the tap water is "hard" due to mineral content or if there is any question in your
mind about water purity. Unclip and remove the top of the external water tank. Wash
the container weekly using mild dish soap. Rinse the tank after washing to remove
soap residue. Replace cover and check hose connections. Fill with fresh, clean water.