Would Reverse Osmosis Water Work?

[ycartf]

Would Reverse Osmosis Water Work in my humidifier tank?

I had to buy a reverse osmosis system (link below) for another reason and I wondered .... would this water be pure enough for my humidifier tank? It would pay for itself over time if it would work, as I would not have to buy anymore distilled water (and lug it around). Thanks for any thoughts or info.

http://www.ebay.com/itm/110581413778?ss ... 1439.l2649

[jamiswolf]

Ycartf,
Sure...I use RO water that's delivered to my house as drinking water. I'd love to have my own RO machine. Most quality RO machines will drop dissolved solids down to below 25ppm. Ordinary tap water can run 200 to 500ppm.

I have noticed no visible residue in my humidifier.
Jamis

[JohnBFisher]

I definitely agree with Jamis .. RO is an excellent alternative to distilled water. Due to the costs, I would not recommend it as the primary approach. But if you already have an RO filter, then it's a good option for your humidifier.

[bwexler]

I have been using RO water for a year in S9 humidifier.
Don't know if it is officially sanctioned but it works for me.

[Mary Z]

I've been using RO water for 3 1/2 years without problems.

[ycartf]

Thanks guys!

Jamis - This filter says it actually drops it down to 0 ppm. It has a 5 micron sediment filter, then an activated carbon filter, then the RO membrane, and lastly a de-ionized filter. It is a neat little portable unit (you can see it on eBay at the link in my first post).

JohnB - I don't find it very cost-prohibitive at all (at least not with this unit). I only paid $82 for the thing, including shipping and 3 extra filters (all but the RO membrane; it lasts from 2-3 years and the others have to be replaced every 6-12 months or at 1000 gallons). That comes to about the same total as 87 gallons from Wal-Mart (the cheapest I have found) after tax. Not to mention that I don't have to lug several gallon jugs around with me.

I hooked it up to the laundry room sink and tried it out just now. It makes a gallon of RO water every 20-22 minutes. I just leave it sitting with the hose threaded into the handle of a gallon jug from the inside, and with the waste hose (it uses about 3 gallons of water for every 1 it makes) dunked into our upright washing machine tub so it will get used washing clothes and not just wasted (it is still potable just like out of the tap, just unfiltered).

[JeffL]

(it uses about 3 gallons of water for every 1 it makes) dunked into our upright washing machine tub so it will get used washing clothes and not just wasted (it is still potable just like out of the tap, just unfiltered).

It's not "just like out of the tap". Whatever got filtered out is in the "waste" water, so it has a higher concentration of the undesirables than the tap water. I'm sure it's fine for your laundry though.

If it taste good for drinking, there must still contain some minerals, but some people here are content using tap water, so it's a personal decision. I don't find it anymore inconvenient to bring a gallon of distilled water back from the store, than a gallon of milk, or a couple of liters of Coke. Before we got our current refrigerator, which dispenses filtered water, I use to lug gallon bottles of drinking water home anyway. Come to think of it, I still lug home cases of small water bottles. It's just not an issue.

[archangle]

Jamis - This filter says it actually drops it down to 0 ppm.

I don't think zero is ever possible, even in a commercial reverse osmosis system. That claim makes me suspicious about that particular unit in general.

Another thing to watch out for is how many gallons of water you get before you have to replace some of your filters. Depending on the type of machine, filter lifetime varies with water quality, and tends to be for a certain number of gallons, not a certain amount of time. Also some filters only filter for a while, and then start letting stuff through until you replace it. There may not be any indication that it's used up or you have to check it somehow. How do you know your filters are used up in this machine?

I believe most RO systems work on a percentage basis. They reduce the percentage of certain things dissolved in the water. They don't completely eliminate it. One RO system may reduce a certain chemical a lot more than another RO system.

That said, done properly, reverse osmosis water is almost certainly better than tap water, even if it's not as good as tap water. The water from almost any filtering system is probably better than regular tap water. For that matter, tap water isn't necessarily wrong, it's just not as good as distilled water if you can easily and cheaply get distilled water.

[jamiswolf]

Archangle wrote: I don't think zero is ever possible

Correct...not with a RO unit. But I used an RO unit for years and when it was new, I'd get around 20ppm water and that's starting with water that was over 300ppm. Mind you this was all vulnerable to the errors of a hand held TDS meter. Even after years of use...with good maintenance, I'd still get 30ppm

Archangle wrote: I believe most RO systems work on a percentage basis. They reduce the percentage of certain things dissolved in the water. They don't completely eliminate it. One RO system may reduce a certain chemical a lot more than another RO system.

Not necessarily...you can take a given RO unit and feed it high dissolved solids tap water and it will still bring it down to very close to it's rated TDS. It'll just clog the filters faster. And interestingly enough, a low cost low output unit can actually produce very clean water. Just not in high volume per hour.

ycartf,
Like Archangle said, you have to watch advertising claims. You could get a meter to monitor quality. So are you an aquarium keeper or a hydroponic gardener?

It's especially important to change the carbon filters because their main role is to remove chlorine. Reason for that is...chlorine will destroy the actual ro membrane.
J

[Ticman]

Wouldn't a home water distiller be just as easy?

[jamiswolf]

Ticman wrote: Wouldn't a home water distiller be just as easy?

Hi Ticman,
I actually used a one gallon Sears distiller and they work good. But it takes about 5 hours for a gallon of distilled water and in hot weather it adds heat and humidity to a room.

If you were only needing distilled water for the humidifier, I'd say yes, go for it. But many of us use the RO water for cleaning as well. I wash with tap water but I always do the final rinse with RO water. The original poster already has an RO filter...so for him, we were just giving re-assurances.

But if you're careful and only need a gallon a day, a distiller would be fine.

One final issue, the distiller builds up scale depending on how hard your water is...and that needs to be soaked with vinegar and cleaned daily. So in my mind, it's a lot of dinking around for one gallon a day of distilled water. Sure you can get much larger distillers...but those are mucho dinero.
J

[archangle]

Don't forget to consider the cost of electricity to run the distiller, and the cost of additional air conditioning, if applicable, for home distilling.

[chunkyfrog]

Our Sears distiller is still running fine; but as it is with all things, the end awaits.
And the distiller is bulky, taking up valuable space in use and storage.
The quick, low-energy processing time of OR is tempting.

[Mr Bill]

It should be fine. There is a thing in chemistry called a solubility product. Basically it states that things start precipitating when the specially computed 'product' (which is more like a sum but with multipliers for charge) of the components reaches a limiting value. Take calcium and sulfate. The Ksp for those is 4.9E-05.
http://www.ktf-split.hr/periodni/en/abc/kpt.html
So if the total molar concentration of the sum of the two (calcium and sulfate) exceeds 4.9 x 10^-5 then its going to precipitate. You can have a lot of one and a tiny bit of the other but only when the solubility product is exceeded do you expect precipitation. But RO water is so low in dissolved solids, that it is unlikely to occur unless you evaporate nearly all the water. Tap water on the other hand, may be near the saturation point right out of the tap, depending on the source of your local ground water.

If you examine that table you will notice that the solubility product for PbS, HgS, and other sulfides are exceedingly tiny numbers. This is good. It means that in natural systems, introduction of a little bit of sulfide, will remove most toxic metals from water, by making them insoluble. So water moves through aquifers and sulfide sources in the aquifer will force toxic metals to precipitate. Iron sulfide (pyrite) is quite common but its presence in rocks makes other more toxic metals, that have smaller solubility products, more likely to be removed. All other things being equal.