QUOTE (Giovanni Pasta @ 12 Jan 2013, 00:43)
<{POST_SNAPBACK}>I am not sure how to measure for total disolved solids, ....., I know people use it for topping up car batteries, also in electric steam irons, so the solids must be quite low, or the irons would scale up just as they would if you were using tap water. ....... my worry of using RO water was the fact Hornby said it would disolve the solder used on the boiler, but as you say it would have to be of a very high quality for it to do that, It would be interesting if anyone on here has used RO water for a reasonable period of time, and suffered no damage.I have used home made reverse osmosis (RO) water ALL the time for several years, and I have not had a problem with RO water. I use a GE device to make it, which I cited above, and I have never used distilled water. I do not know the total dissolved solids (TDS) of RO water sold in the UK, so you need to measure it, and compare it to my RO water which has 5-6 ppm TDS. Above, I gave the brand name, Hanna, of the inexpensive device I use to measure the TDS of RO water. The price of the Hanna device is likely only the cost of a few bottles of Hornby distilled water.
The same goes for bottled RO drinking water. I would measure it. I have seen bottles of drinking water with the TDS written on the labels, but it is usually because the water is "spring" water which is supposed to have "healthy" and "natural" minerals in it, so the TDS will be of the order of up to a couple of hundred ppm. The companies that sell spring water want you to know about the minerals, so they say so on the bottle. "Spring water" is not RO water. Don't put "spring" water into your locos for sure. Some spring water may have fairly low TDS, for example I measured one the other day that had 25 ppm TDS. I don't put that in my locos. It says on the bottle "collected only from natural springs" and "100% natural spring water".
Dissolving solder may be a possibility for scientific deionized water, which is even lower in TDS than my RO water, but as Hornby has pointed out the likely problems, I do not plan to try that in my locos, even though I have access to it! Regular RO water used for drinking is not scientific deionized water, even though it could be called "deionized". Scientific deionized water is treated in ways additional to just reverse osmosis, including several different types and stages of reverse osmosis, ion-exchange, and carbon filtering.
Based on my measurements, observations, and usage I have concluded the following:
Scientific water - very low conductivity, low TDS - don't use
Bottled Spring water - variable TDS and too high for Hornby LS - don't use
Home made RO water - check the TDS but likely ok for Hornby LS
Bottled RO water - check the TDS but may be ok for Hornby LS (I need to do this measurement)
Tap water - check the TDS but almost certainly too high for Hornby LS
Distilled water - low TDS - recommended for Hornby LS
Rain and snow water - low TDS may be ok if there are no large particles in it. Can't be filtered without contaminating it.
Dehumidifier water, fridge water, and similar - full of evil contaminants from your house - don't use it in your locos.
If the water tastes bad, don't use it too!
