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A jug of distilled water on a cabin shelf raises the question every time someone reaches for a drink: is distilled water good for you? Distilled water is plain water with minerals removed by boiling and condensing, so it is water without the minerals that tap water or spring water carries. Whether it suits you turns on the rest of your diet, since food is the other source of minerals, so this guide explains what distillation removes, where mineral-free water is used, and what this guide does not answer.
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Is distilled water good for you, and where is it used?
Distilled water is water that has been boiled into steam and condensed back into liquid, leaving minerals behind in the boiler. It carries no minerals of its own, so it adds none to the diet, and the minerals a body needs come from food as well as water. That is the whole answer in brief: distilled water is water without minerals, and the question of whether it is good for you is a diet question, not a water question. A clinician can advise on drinking water for your own diet.
What distillation removes
Distillation boils water and condenses the steam, and the minerals stay behind in the boiler. Tap water carries minerals from the ground and from treatment, and spring water carries minerals from the rock it passes through. Distilled water carries none of those minerals, which is why makers call for it where deposits would cause trouble.
| Water | Minerals | Common uses |
|---|---|---|
| Distilled | Removed by boiling and condensing | Batteries, irons, humidifiers and labs |
| Tap | Carried from the ground and treatment | Drinking and cooking |
| Spring | Carried from rock | Drinking |
The table shows the split in plain terms: distilled water is the water with minerals taken out, while tap water and spring water keep the minerals they pick up on the way.
Where distilled water is used
Distilled water shows up wherever minerals would leave deposits or skew a result. The main uses are:
- Batteries: flooded lead-acid batteries take distilled water for top-ups, because tap water leaves minerals behind in the cells. See our deep cycle RV batteries for battery types that use it.
- Irons and steamers: steam irons and garment steamers call for distilled water so minerals do not clog the steam vents.
- Humidifiers: humidifiers use distilled water so minerals do not settle as dust and scale inside the tank.
- Labs and aquariums: labs and aquariums use distilled water where a known, mineral-free starting point matters.
For solar setups, the battery use is the relevant one: see our batteries guides for battery types, and our power stations guides for the units those batteries feed.
How to tell distilled water from other water
Store-bought distilled water says so on the jug, and the label names distillation as the process. Tap water comes from a faucet and carries the minerals of its source, while spring water names a spring on its label. If the label does not name distillation, the water is not distilled, whatever the jug looks like. Keep the jug closed between uses, since an open jug picks up dust from the air, and store it away from strong smells, which water absorbs through an open cap.
Distilled water in a solar setup
Batteries are where distilled water meets a solar setup. Flooded lead-acid batteries lose water as they charge and discharge, and the maker manual calls for distilled water to top up the cells, because tap water leaves minerals behind. Check the level through the caps and top up with distilled water to the line the manual gives, and keep the caps closed between top-ups so dust stays out. Sealed batteries and lithium batteries take no water at all, so the top-up rule covers flooded batteries only.
Keep a jug of distilled water with the battery bank so top-ups happen before the plates show above the water, and label the jug so nobody pours it into a drink. A jug kept for batteries stays with the batteries, not on a kitchen shelf.
Distilled water and drinking
People do drink distilled water. It is water with the minerals removed, so it adds no minerals to the diet, and the minerals a body needs come from food as well as water. Bottled spring water and tap water carry minerals, while distilled water does not, so the choice between them turns on diet rather than on the water itself. Anyone with a diet question about drinking water should ask a clinician, who can advise for that diet.
What this guide does not cover
This guide gives no personal health advice and no verdict on whether distilled water suits your diet; a clinician can advise on drinking water for your own diet. It gives no mineral figures, because no figure in our reference listings describes drinking water. It does not cover generator covers or home wiring, which belong to other guides on this site.
FAQ: power away from the grid
Can I use distilled water in a battery?
Yes, where the battery maker calls for it. Flooded lead-acid batteries take distilled water for top-ups, because tap water leaves minerals behind in the cells. Check the battery manual for the water it calls for.
Is distilled water the same as purified water?
No. Purified water is water that has been filtered or treated to remove impurities, while distilled water is water that has been boiled and condensed. Distilled water is a kind of purified water, but not all purified water is distilled.
Can I drink distilled water every day?
People do drink distilled water. It adds no minerals to the diet, so food is the other source of minerals. A clinician can advise on drinking water for your own diet.
Why do makers call for distilled water in irons and humidifiers?
Minerals in tap water leave deposits in irons, steamers and humidifiers, and distilled water has those minerals removed. Follow the maker manual for the water it calls for.
Related solar guides
See the batteries, the deep cycle RV batteries and the power stations guides.
