"In the deionizing process, the contaminated water passes through two columns full of ion exchange media, one of which is saturated with sulfuric acid, the other sodium hydroxide. The H+ from the sulfuric acid replaces any cation contaminants in the water, while the OH- from the sodium hydroxide replaces any anions.
Some people feel that deionized water (especially if a mixed bed deionizer was used) is so pure that it is very aggressive and unsafe to drink. "
I wouldn't be comfortable drinking water that comes out of a tube that was recently filled with liquid caustic or concentrated sulfuric acid.
Maybe RO before the Deionizer..besides its so pure i dont think it would quench your thirst