you will usually find that the only way to give them distilled water is if the water has minerals in it.
Ah, thank you for the admission! You CANNOT use "distilled water" in aquariums. You MUST add components of natural water back into it, or it's good bye fishies.
Distilled water with added minerals is, uh, no longer distilled water.
The night has come upon us, and we have but two choices: to fear it, or to face it bravely while looking to the Light that cannot be overcome. John 8:12