TDS Readings

[imported_DetailDan]

Took some TDS readings, thought some might find this interesting.



Tap water- 214ppm

Sprinkler water- 204ppm

Hose water- 198ppm

Bottled water- 20ppm

Filtered tap water- 18ppm

Rain- 16ppm

CR Spotless- 000ppm :rockon:

[Bill D]

Gotta love 0ppm from the CRS! :)



I`m surprise the tap water and hose water are that different.

[Dan]

My tap water is right in the 250ppm range. My RO`d drinking water is in the 18-20 range. Need to check out the rainwater!

[wascallyrabbit]

My tap water is right in the 250ppm range. My RO`d drinking water is in the 18-20 range. Need to check out the rainwater!



if you a di cartridge to the end of your ro you could get 0ppm.

[David Fermani]

Great info. I thought rain would have more? I wonder at what level is it safe to assume that spoting won`t occur from the water source?

[Bill D]

Great info. I thought rain would have more? I wonder at what level is it safe to assume that spoting won`t occur from the water source?



The folks at CRS told me to change the resin at 20 but if it`s observed that spotting occurs from rain water at 16, maybe 20 is just wishful thinking? :confused:

[David Fermani]

Good point Bill. I know out on the west coast they have dispenseries for RO water. Detailers basically roll up with their truck, put in a few quarters and a large volume of water fills up their tank in a matter of minutes. Neat concept. I wonder what % they go by before changing filters?

[C. Charles Hahn]

The folks at CRS told me to change the resin at 20 but if it`s observed that spotting occurs from rain water at 16, maybe 20 is just wishful thinking? :confused:



It may depend on what exactly the 16-20ppm is made up of, too.... I would think there are a lot of environmental factors that could determine what TDS level is acceptable before spotting occurs.

[Dan]

Great info. I thought rain would have more? I wonder at what level is it safe to assume that spoting won`t occur from the water source?



Isn`t rainwater essentially distilled?

[imported_DetailDan]

I believe other factors include what is on the paint when the water dries, temperature of the paint, angle of the panel (horizontal or vertical) and what other contaminants are in the water that the TDS meter does not read.



Im sure the rainwater we get in VA is not the same as what you`ll find in NY, FL, etc.

[Ch96067]

Interesting subject Dan. The rain water reading makes sense now. When it rains in Athens (not the one in Georgia :) ) and the car stays under the sun afterwards there are no water spots. However, leaving the car with the hose water on even for 15 mins is a recipe for disaster.



Collecting rain water for washing the car sounds interesting...

[Dan]

Collecting rain water for washing the car sounds interesting...



I have considered it but there are issues with storing the water long term, and algae is a huge one of them.

[wascallyrabbit]

they have some chemicals you can add to kill the algae not sure how it would affect the paint. Purogene is a water treatment for long term storage of drinking water.

[togwt]

I believe other factors include what is on the paint when the water dries, temperature of the paint, angle of the panel (horizontal or vertical) and what other contaminants are in the water that the TDS meter does not read.



I`m sure the rainwater we get in VA is not the same as what you`ll find in NY, FL, etc.



Water Supply Classifications (Water Quality Research Council)



For those of you who are wondering how hard the water in your area is, here`s a general map you can use –



What Is My Water Hardness? - United States Water Hardness Map, What is my water hardness? (http://qualitywatertreatment.com/city_water_guide.htm)



• Soft Water- 0 to 1 grains per gallon

• Slightly Hard Water- 1 to 3½ grains per gallon

• Moderately Hard Water- 3½ to 7 grains per gallon

• Hard Water - 7 to 10½ grains per gallon

• Very Hard Water - over 10½ grains per gallon



Hard Water



Hard water has high concentrations of Ca2+and Mg2+ common calcium-containing minerals are calcite and gypsum. A common magnesium mineral is dolomite (which also contains calcium). With hard water, soap solutions form a white precipitate (soap scum) instead of producing lather. This effect arises because the 2+ ions destroy the surfactant properties of the soap by forming a solid precipitate (the soap scum). A major component of such scum is calcium stearate, which arises from sodium stearate, the main component of soap:



Milligrams per litre (mg/l) or Parts per million (ppm)



A reading of ~ 0 - 15 will avoid `water spotting`



Soft: 0–60 mg/l

Moderately hard: 61–120 mg/l

Hard: 121–180 mg/l

Very hard: ≥181 mg/l

[Dan]

^^^^ Sweet cut and paste non answer!