LFS told me the RO is the same as distilled - true or false?

[jimrawr]

I called up one shop to see if they sell RO water for when I fill my tank this week. He told me that the RO water turns into distilled water so I might as well just get distilled from the super market.

Any truth to that? What exactly is the difference between RO and distilled?

[jimrawr]

Is it better to use RO or Distilled water when first filling a tank?

[EdKruzel]

Either or, it really doesn't matter; each should have little to no TDS's.
Most do, but be sure whatever salt mix you have comes with a buffer.

[WaterKeeper]

Hi Jim,

Depends on the distillation system used to make the bottled water. A good TFC RO membrane removes about 98% of the material entering the system. Water from a quartz or glass still can be closer to 99.9%. If one uses RO followed by DI you beat the other two hands down as they produce water very close to 100% pure when functioning properly.

There was some concern in the past over distilled water that passed through a copper condensing coil. With the advent of EPA drinking water copper limits most all quality distilled water does not contact copper coils.

See [rodifaq] for more on the subject.

[jimrawr]

Im guessing its OK to mix the two right? I.E 20 gallons from LFS RO water, and 10 gallons distilled from super market

[patsverizon]

You will be fine mixing the 2 if that is what you would like to do. I ususally use filtered water from a glacier machine at my local grocer. It says it is RODI filtered goes though a carbon filter and a double pass of UV light... 39 cents per gal and I have never had any issues with algae or water quality.

[danch]

"RO water turns into distilled water"?

Huh? Does that make sense to anybody out there?

[Alex_GSO_NC]

im a newb here... however distilled to me in a basic definition sense means that water is: undergo condensation; change from a gaseous to a liquid state and fall in drops;

from heating.. RO or whatever is through osmosis ands tuff and filtering or whatever..

[dwculp]

In the absence of an RO/DI machine, distilled water from the supermarket is an acceptable substitute. I have been using it for 2.5 years and it normally reads 0 TDS.

[AZDesertRat]

I have yet to see a water vending machine that is RO/DI. You might want to double check that, its probably RO followed by UV.

[WaterKeeper]

Right On Alex,

Distilled is merely water that is boiled into steam and re-condensed; whereas RO uses a membrane to to remove impurities much like a super filter. I didn't mean to confuse the two Danch.

I'm with you Rat. Supermarket units that I've come across do not use DI as a final stage. However, using bottled distilled or RO from a machine is far better than using tap (unless you get it directly from that glacier )

[danch]

Your post was fine, Tom. I just noticed the statement that I quoted as what the LFS guy told the OP, and wondered how it could make any sense for one to 'turn into' the other when the names of them are based on how they're processed. Sometimes my brain goes "Pwang!" when I see something that seems logically inconsistent, and when nobody else comments I feel like I might be missing something that makes it make sense.

Thanks once more for all the knowledge you've shared.

[dwculp]

All I know is I have almost never encountered bottled distilled water that has a TDS above 0.

[EdKruzel]

Originally posted by dwculp
All I know is I have almost never encountered bottled distilled water that has a TDS above 0.

That was my point as well. 0 TDS is what you're shooting for no matter how the water was prepared. Although I didn't properly answer the question. (Tom was on it, Thanks Tom)
Our machined water (The Water Mill ) uses DI as their final stage, however maintenance of the unit is what is questionable here.
A good pocket TDS meter is a wise investment.

[dwculp]

Originally posted by EdKruzel
That was my point as well. 0 TDS is what you're shooting for no matter how the water was prepared. Although I didn't properly answer the question. (Tom was on it, Thanks Tom)
Our machined water (The Water Mill ) uses DI as their final stage, however maintenance of the unit is what is questionable here.
A good pocket TDS meter is a wise investment.

Yep, the two best things I ever bought were a TDS meter and refractometer.

I just didnt want people getting bottled distilled water confused with the water that comes out of the machine.