Softened tap water for cooling system?

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All this talk of "manufacturers recommendations" got me curious, so I checked out the owners manual under Engine Coolant:

"A 50/50 mixture of clean, drinkable water and DEX-COOL coolant will :
- Give freezing protection down to -34F
- Give boiling protection up to 265F
- Protect against rust and corrosion.
- Help keep the proper engine temperature.
- Let the warning lights and gauges work as they should."


a few pages later:


"If coolant is visible but the coolant level isn't at or above the FULL COLD mark, add a 50/50 mixture of clean, drinkable water and DEX-COOL coolant..."


Sounds like I'm covered either way, as GM doesn't sound that particular as to what kind of water is used.

But... oh no! I might have turned this thread into a DEX-COOL hate fest as well!

I'll be in my bomb shelter if anybody needs me...
 
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It's amazing what can be learned when you open the manual and read it. And, a time saver too.

Of course, like oil viscosity recommendations not all manufacturers are the same.
 
I've used tap water forever too. The people who use tap water and actually drain on some sort of regimen will have water pumps cores and radiators live a long long life, side by side with dealer serviced or distilled changes as well.

I'm gonna say it's similar to the extended interval with synthetic oil argument. A consistant change of "inferior" product with fresh additives vs something that's a proven long miles runner, tough choice.
 
From Nissan 03
"When adding or replacing coolant, be sure to use only a Genuine Nissan Anti-Freeze coolant (green) or equivalent with the proper mixture ratio of 50% demineralized or distilled water. The use of other types of coolant colors, such as orange may damage the engine cooling system." Crystal clear.

From Toyota 01
"Read the coolant container for information on freeze protection. Follow the manufacturer's directions for how much to mix with plain water (preferably demineralized water or distilled water)."

With the increasing use of aluminium engine components has come the increasing manufacturers' recommendation for the use of distilled water. On older models, I've used tap water and a flushing T. Now though, I use multiple distilled water drain/fills before final fill. Different engine component composition and recommendations.

All that said, use what want or are comfortable with. I know what I'm comfortable with.
 
There are too many contaminants in our water here. The water will plug a shower head up with Calcium in 2 months.

It does the same thing to the tubes in radiators in about 6 months. So depending on where you live you could or could not use tap water.

Deionized tap water is ok to use.

Distilled water is ok to use.

Softened water is not recomended. Many softeners use salts to soften the water. The salts left over in the water will attack the cooling system.
 
Originally Posted By: Chris142


Softened water is not recomended. Many softeners use salts to soften the water. The salts left over in the water will attack the cooling system.



That's the part that intrigued me the most of what I quoted. The last sentence:

" Many mistakenly believe that because SALT is added to water softeners, softened water must contain salt, a substance known to be very corrosive. Nothing could be further from the truth. The salt that’s added to a water softener is NaCl, or sodium chloride. During the softening process, only the sodium ion is exchanged into the water, whereas chloride ions are removed when the softener is regenerated. Therefore, softened water does NOT contain corrosive salt."


The belief that softened water contained salt was why I had never used it in the past. If it IS true that softened water contains no salt and is also demineralized, it seems like it would be perfectly fine for cooling system use.


I guess what I would really like is people's thoughts on whether softened water actually has any salt in it or not.
 
Originally Posted By: sayjac
And, before the manufacturers started recommending distilled water, I used to use a flushing T and tap water.


That's why all those plastic flushing T systems must be priced so cheaply at Walmart (only $2.xx). There's probably a huge inventory in a warehouse, and they're trying to unload'em cheap.

I bought one just to read the instructions for it, but I wrote on the instructions: "Never use this."
 
According to Culligan, a gallon of their softened water "has about the amount of salt as a head of lettuce." Of course they are addressing the health concerns of softened water.

Systems that use salt must have some salt but not very much. It washes the media that demineralizes the water with salt then rinses the media with clean water. My mom's house has had a water softener for 25 years and she has no noticeable rust from the iron pipes.
 
If you take your own containers, you can get highly purified water at Wal-Mart for $.33/gal. Why mess with tap water?
 
We just had our water tested from Culligan to test the effectiveness of our Reverse Osmosis unit and we found out that there is only 2ppm of salt getting through the unit. So I will just use the R.O. water on my next change.
 
Thanks Stevie. I found the below about the salt content of different types of distilled water. It looks like your RO water is approaching the purity of triple distilled water.

"Type-I Grade:
Resistivity:.... 18 Meghom.cm minimum
Sodium:......... 1 ppm maximum
Chloride:....... 1 ppm maximum
Silica:.......... 3 ppm maximum
TOC:............ 50 ppm maximum

Type-I grade water is usually prepared by triple distillation or by single distillation followed by DI (to minimize TDS) and AC filtration (to minimize TOC) if necessary. Alternatively, in a continuous set up, RO water is used to feed a DI unit (mixed-bed ion-exchange resins) to achieve Type-I grade. Often, to ensure consistent quality, several purification stages are combined: coarse filtration, AC filtration, RO, and DI. In all cases, micro-filtration with 0.22-micron filter must be used. Type-I grade water is used in the semiconductor and pharmaceutical industries.

Type II Grade:
Resistivity:.... 1.0 Megohm.cm min.
Sodium:......... 5 ppm max.
Chloride:....... 5 ppm max.
Silica:.......... 3 ppm max.
TOC:............ 50 ppm max.

Type-II grade is the typical quality of single-distilled water. In practice, AC filtration, or RO or DI is often used to treat the water before distillation to achieve Type-II grade water consistently."

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1132333988&openflup&1&4



I guess I've found the answers to my questions:

1. Softened water DOES contain residual salt, although in very small amounts.

2. Softened water further treated with reverse osmosis has the same low salt levels of distilled water.


OK, I'm done splitting very fine hairs.
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My dad thought it was the cause of his blood pressure, so we took 3 samples of water to Culligan for testing. One straight from the well, one after the filtering/softening/iron removing units, and one after the R.O.

There was so little salt left in the water after the RO that they said he would get more salt from eating one slice of bread than from a 2 litres of water from the RO unit.

Needless to say he was happy with that answer!
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The guys at Culligan know their sutff and are really great!
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