RO/DI Waste Water

csmsss

Member
RO units ARE used for purifying drinking water, absolutely. The question is: After water has passed through the DI Resins, is it then "safe" to drink?
If it was safe prior to passing through the R/O filter, then it's certainly safe to drink afterwards. Some of the previous posters would have you believe that somehow the R/O membrane magically ADDS minerals to the wastewater, which is ludicrous.
 

steved13

Well-Known Member
PREMIUM
I'm still trying to learn. Isn't the waste water the stuff that didn't go through the filter? It would make sense to me that if it went though the filter it wouldn't be waste water it would be filtered water. The waste would be the stuff that didn't go through. I'm thinking it's like any other filter..it filters out the bad stuff "the waste" and lets the good stuff pass "filtered". I wouldn't want to drink the stuff that didn't pass through my drinking water filter, but I would drink the stuff that went through, and I would drink the water before it went in, but not that waste.

I gather from your post there is something I don't understand and it works differently.
 

Luukosian

Well-Known Member
I suppose to look at it in a different way...if you are just concentrating levels of minerals etc. that are in the water to begin with. Drinking 1 glass of wastewater would be like drinking 4 out of the tap(just a hypothetical number) as far as "contaminates" go. I'm pretty confident I could drink as many glasses of water out of my tap without it harming me.

As long as it tastes ok I would be fine with drinking the waste water. Guess I've never tested TDS of waste water either...anyone got any numbers?
 

steved13

Well-Known Member
PREMIUM
I suppose to look at it in a different way...if you are just concentrating levels of minerals etc. that are in the water to begin with. Drinking 1 glass of wastewater would be like drinking 4 out of the tap(just a hypothetical number) as far as "contaminates" go. I'm pretty confident I could drink as many glasses of water out of my tap without it harming me.

As long as it tastes ok I would be fine with drinking the waste water. Guess I've never tested TDS of waste water either...anyone got any numbers?

Your logic is flawed, all contiminants in drinking water have "safe levels" if they are concentrated to high they are "unsafe" it's not like dinking more glasses. If that were the case there would be no such thing as safe concentrations, and unsafe concentrations.

In your hypothetical example the concentration changed from 25 ppm to 100ppm or 250ppm to 1000ppm. If the safe level were 300ppm the danger level were 500ppm, and the fatal level were 800ppm you went from potable to deadly. I doubt any contaminents would fall into this category, I'm just illustrating the flaw I see in your logic. It would be kind of like saying "I see no problem with a pollutant level 10 times the target range in my aquarium, it's just like have an aquarium 10 times larger". Yes, the numbers add up, but the effect is much different. Many people, confuse quantity with concentration...they are not interchangable?

You are probably correct, I doubt any contaminents go from safe to a problem at 4 times the level, but it is not the same as drinking 4 glasses of water instead of 1.

Why would anyone want to drink the waste water anyway? LOL
 

steved13

Well-Known Member
PREMIUM
RO units ARE used for purifying drinking water, absolutely. The question is: After water has passed through the DI Resins, is it then "safe" to drink?

No. Someone is asking, if the waste that was filtered out is "safe to drink".
 

Luukosian

Well-Known Member
If you're talking thousands of orders of magnitude and you have something like organophosphates in your water I suppose your right but I don't think thats the case here. We're talking under 10X magnitude tops...if your drinking water is that bad you probably shouldn't be drinking it out of the tap!
 

steved13

Well-Known Member
PREMIUM
If you're talking thousands of orders of magnitude and you have something like organophosphates in your water I suppose your right but I don't think thats the case here. We're talking under 10X magnitude tops...if your drinking water is that bad you probably shouldn't be drinking it out of the tap!


Please go back and read my post (please read all the words, this time). I think you'll find where I said the same thing. This is true, it's your logic that I said is flawed, not the answer.

As in:

You are probably correct, I doubt any contaminents go from safe to a problem at 4 times the level, but it is not the same as drinking 4 glasses of water instead of 1
 

BLAKEJOHN

Active Member
It is infact safe to drink the DI water also. It will not kill you, BUT DI has no minerals that you do need. It Is Not A Good Idea to drink DI water on a regular basis.

The waste water is definatley OK to drink. It is not safe to drink large quanities nor is it safe to drink large quantities of any water. But the normal consuption of RO waste water is just fine.

Just do not obsess about using all the waste water and drink it all...LOL.

Now we dont drink my waste water and if you seen our tap water you wouldnt drink that either.
 

mbdave

Active Member
What I do is
1. Run my waste line through another membrane. You need I believe 65 psi to do this.
2. In the past I ran my waste into 55 gallon drums "you can get used ones pretty reasonable" and used it for watering the yard and garden, wash the car, dog and such.

Dave
 

BLAKEJOHN

Active Member
I wonder how that unit gets 1:1. Unless the waste water is t-d back into the feed line.

I have basicaly the same unit. with the addition of a second membrane and my pump in pre-filter running at 75 psi.
 

steved13

Well-Known Member
PREMIUM
I was reading up a little on RO-DI. From what I gathered most of the waste ratio is due to lack of water pressure. The "holes in the membrane pass clean water and stop contaminants, with lower pressuer there is nothing from stopping some of the water from coming back the "wrong way" through the membrane and going out with the waste. More pressure keeps more "clean water" on the correct side of the membrane. The pressure pump in the unit does the job. If yours has a pressure pump I would think your gettenig better then the 4 to 1 ratio of most? Im figuring even if this unit doulbes the concentration of contaminants it isn't enough to do you any harm, but I was wondering.

Again, I don't even drink it straight from the tap with out going though a faucet filter, let alone would I drink the waste, but now I'm curious.
 

csmsss

Member
It is infact safe to drink the DI water also. It will not kill you, BUT DI has no minerals that you do need. It Is Not A Good Idea to drink DI water on a regular basis.

The waste water is definatley OK to drink. It is not safe to drink large quanities nor is it safe to drink large quantities of any water. But the normal consuption of RO waste water is just fine.

Just do not obsess about using all the waste water and drink it all...LOL.

Now we dont drink my waste water and if you seen our tap water you wouldnt drink that either.
This is misinformation. Not that DI water isn't safe to drink, of course - because it is every bit as safe to drink as unfiltered tap water, and in the same amounts. That is, of course, unless you're on a starvation diet. Any essential minerals you might be getting from water you should also be getting from your normal diet. You are not starving your body of nutrients just because you're drinking DI water.
 

BLAKEJOHN

Active Member
You went high end and didn't know it?

I guess so... Really I got the pump because my water pressure is only 28psi and I knew I need more like 65psi. Also to make a little water a little faster and reduce the well pump from running. Then I got the second membrane to increase my product water, didnt think it would decrease the waste so much..
 
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