Alternative watering method?

Currently I buy distilled water at the store by the gallon for about 75 cents per gallon. I buy the distilled cause its 000 ppm. Then add my liquid nutes to it. Although this method is starting to get costly and I am looking for a new method. How else can I get 000 ppm water other then buying distilled water?

buy a water distiller...it'll cost you at first but then you own it forever.

Live in an area with good water. I use water from my basement faucet, 50ppm and 6.8-7.0ph out the tap! Love it