From The Aquarium Wiki
DI or Deionised. Usually refers to Deionised water. This is water pushed through resin which removes most of the dissolved minerals and metals (typically >95%) from the water. The result is close to pure water with a pH of close to 7. With no or close to zero KH or GH.
- This water is often commoningly found in car accessories shops as it is used to top up the water in car batteries or in supermarkets for steam Irons to stop them scaling up.
- See RO Reverse Osmosis process which is another way to make your own pure water.
- Distilled water is another commercial method used to make pure water. It is typically boiled and the steam collected.
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