What is the "best" water to use for washing a car?

[mckeand13]

Obviously softened so there is no calcium or mag. (also iron) , but I'm wondering if DI water is better for some reason, or any other type of conditioning.

If you have any suggestions, please explain.

Thx.

[gbackus]

Re: What is the "best" water to use for washing a car?

The absolute best is DI polished RO water, which is RO water that is passed through single bed DI tanks(two single bed tanks, one anion, the other cation, as opposed to mixed bed tanks).

Next on the list is regular DI water, then RO water, then distilled water, and finally soft water.

Soft water is pretty low because even though it may spot less, the high sodium content attacks the integrity of waxes/sealants, decreasing longevity.

[Setec Astronomy]

Re: What is the "best" water to use for washing a car?

Hmm...that is the first time I've heard that complaint about soft water, and I've been considering repiping my driveway faucet to soft

[gbackus]

Re: What is the "best" water to use for washing a car?

Hmm...that is the first time I've heard that complaint about soft water, and I've been considering repiping my driveway faucet to soft

I, luckily have access to regular tap water, soft water, and regular DI water at my home so am able to compare all three. Most people only have one or the other, but I have three outside faucets, the front yard has regular tap water, the driveway faucet has RO, and the back yard faucet can be hooked up to my DI tanks.

Another thing with soft water, is that if you ever choose to get DI tanks, is to run only regular tap or RO water through them only, no soft water. Soft water will go through the resin beds a lot quicker.