If you want water with NO nutrients in it at all, buy RO water or a home filtration system. Home RO filtration systems are kind of expensive and very wasteful. You can buy a reliable home set up with a monthly maintanence charge, but if you can find bottled RO water in large quantities, go that route because home system installation usually requires a monthly mechanic to come and change filters and whatnot.

When using RO water, watch for pH as it is much more acidic than tap water

Here are some specs on RO water:

Reverse Osmosis Water Filters and Water Purification