Ro Vs. Di Vs. Distilled Water

[Chunkmuffin85]

Hey I was just wondering what type of water people use in there aquarium besides tap water. Also, does anyone use a DI (deionized) filter and not a RO or RO/DI filter? I was just curious if anyone sees an advantage to using DI water over RO water. To me a DI filter would produce much less waste and is much more cost effective. And you can fill up your car battery if you needed to as well! And does any use distilled water or even own a distilling unit. They are extremely expensive, but it seems worth it because it kills the pathogens and virus's in the water.