How clean is RO/DI waste water?

[bamf25]

SO we all lament how much these units waste. I have heard many people say they use it for luandry or for their house plants. How safe is the waste water for pets, or even just for drinking in comparison to out of the tap? Does this change with a standard units verses the recycling units that are close to 1 : 1 for purified vs waste water?

[TAB]

Thats going to depend on your water and what your raito is.

1:1 for example, will have twice the mineral content of tap water. 2:1 will have about 1/3 more, 3:1 will have about 25%... etc

[bamf25]

So the water will be very clean from a chemical/waste product perspective, but be very hard.

[jeff@zina.com]

RO/DI waste water is filtered tap water, with a slightly higher concentration of dissolved solids. Whatever you do with tap water you'll be safe doing with the RO/DI waste.

Jeff

[bamf25]

Does this include people drinking it?

[herostar]

Yes you can drink it.



I use mine for watering plants and doing laundry. If I had a hot tub I'd use it to fill that... if only I had a hot tub! It's cold here in CO!

[bamf25]

I have a hot tub (well a jacuzzi) but that water is way better hot, and mine does not have its own heater. lol

[alonglongtime]

I have well water. TDS varies at different times of the year. The range is anywhere from a low of 450ppm-over 700ppm. Then there are the great additions of herbicides and pesticides from all of the farming and of course I cannot forget the wastes from multiple dairy farms. Yes, I know it all percs down through the soil and is cleaned to a degree, but I make sure my water is clean and the only thing I do with the RO/DI waste water is use it to water the garden and the yard. Sometimes I use the water I pull from my tank (mixed with well water) to water salt loving plants. Yes, they do exist. I even purify my drinking water. If you have tap water that is even halfway decent, protect it. Do all you can to preserve your communities water supply. In a few years, the federal government will be claiming all water as theirs and then you can complain about water prices being too high at $4 a gallon. LMAO

[bamf25]

^^^

Making things cost more is what government seems to do best.

[greenbean36191]

I don't think it's generally recommended to drink RO waste water due to possible bacterial contamination. Sediment filters, carbon blocks, and the interior surfaces of the housings are good places for bacteria to grow, so although the water might be clean going into the unit, the inside of the unit itself is not. When you run water through, it flushes out some of that bacteria and since it can't pass through the RO membrane, it all ends up in the waste water.

[liquidplumber]

You could add an extra membrane if you are looking to cut down on waste.
I added one to my rodi and cut waste in half. I use the waste water for my garden in the summer but down the drain in the winter.

http://www.bulkreefsupply.com/store/products/reverse-osmosis-filters-and-systems/ro-di-accessories/150-gpd-water-saving-upgrade-kit.html

[RenoR1]

I just checked all my TDS levels for intake, RODI water, and waste. This is what I got

Intake: 77
RODI: 0
Waste: 96

So with those I use the water in the garden all the time. I don't give it to my dogs, although I doubt it would be a problem considering some of the water they find during our afternoon runs...

Edit: After typing that...why don't I use it for my dogs? 96 is lower than most others normal water from what I hear... Premonition I had!

[SA13]

Just restating what greenbean said.

Remember after the water hits the carbon blocks and the chlorine is removed there is much greater chance for bacterial growth.

Edit: This goes for both the RO & waste water.

[Sharpie_]

I know this will probably seem naive, but where is the bacteria coming from? Chlorinated water is relatively sterile going in, why would it carry bacteria with it?

Also, my incoming tds is on average anywhere from 100-130, Reno you're safe.

[ATinPGH]

I give it to the inlaws to drink. Its got to be better than their well water.

[sucker_fish]

I use the waste water to water plants, store it for scrubbing down the patio, and even water the dogs with it, they actually seem to prefer the wastewater to tap water and besides one of them developing an extra leg trying to grow from their neck and an extra tooth growing in the bottom of her mouth there have been no ill effects...

[Rudolph]

Okay, thinking out loud here, so what if you really wanted to be green, could you put the waste water in another tank with just live rock and micro algae and let it do it's thing....(or would it never take out whatever if left over?)...and then use water from that tank for your coral/fish tank? I really hate watching that water run drain.....could save some to water the plants, but that wouldn't put a dent in it....

[jeff@zina.com]

...(or would it never take out whatever if left over?)...
Bingo.

Jeff

[jeff@zina.com]

Keep in mind that water is the least expensive item in this hobby, so RO waste is a minimal cost. Add to that the fact that a 10 minutes shower uses more water than most units waste in a week and you can see how minimal the effect is of any conservation of the waste water.

The idea is great. But you can get better returns elsewhere in your home for less effort. Putting a flow restrictor on that shower for example. :)

Jeff

[Rudolph]

Yes, water is pretty cheap, but I guess you hear so much about water shortages around the country/world I tend to feel a little guilty watching it (water that is probably cleaner than many people drink every day) go straight to the sewer. I lived in your neck of the woods for 18 years (Naples) and know Florida had water restrictions for a several years when I was down there so maybe that is lingering on my mind. However, I am certain no one died from lack of water so maybe it wasn't that big of a deal...maybe a mercedes didn't missed a wash day...lol

Anyway, I will check to make sure my flow restrictors are in place, but I wonder how long it would take to cleanse the water side of my RO/DI in a 55G tank with LR and macro algae? Anyone have any ideas or is that a waste of time? Of course the down side is I would use electricity to run the tank so it probably would negative the whole green idea unh?

[spieszak]

RO/DI waste water dumped in your yard puts it right back into nature from whence it came. You're only "really" adding to the problem if you run it down your drain if it is run to a sewage plant where they spend major resources cleaning your clean water.. (which if you have a septic isn't the case) You still have the "how it got to your house" side, but your cutting it in half by not sending it back.

[leedoherty]

I run my waste into a water butt for the plants not that i ever use it
Its always raining in the uk

[INSPECTOR]

Water is not that cheep. I'm on a well and the tdc going into my rodi unit is 9ppm, coming out is 0ppm. Sence my waste water is probably 10 times better than most others clean water, I use it on my plants and fresh water tank.

[reefsurfing]

I have my ro/di setup attached to my washer connections and I simply run my waste into my washing machine, then, I do a load of laundry.

[Rudolph]

Okay reefsurfing gets the gold (or green in this case) star....:lol:

[Rudolph]

...gets...

[fishdip]

waste water ...

[breiter3]

TDS of 9?! Wow. Mine will creep UP to 9 on the output when my DI is exhausted. Amazing. My tap TDS is in the 400-500 range though. I use my waste to fill the resivoir on my EarthBox veggie planters year round. The rest is used for laundry, cleaning, dogs, and anything else I can think of at the time. Not much ends up going down the drain.

[bamf25]

I think I can drink my waste water. I finally got my unit today, water into the DI canister is 5 to 20 tds, obviosly out is 0. I have not tested the waste water yet, but if my input is often in single digits, I bet my waste water is just fine.

[GR214]

I have tasted it before in all honesty its good water.

[steamman]

I don't think it's generally recommended to drink RO waste water due to possible bacterial contamination. Sediment filters, carbon blocks, and the interior surfaces of the housings are good places for bacteria to grow, so although the water might be clean going into the unit, the inside of the unit itself is not. When you run water through, it flushes out some of that bacteria and since it can't pass through the RO membrane, it all ends up in the waste water.

If that were true then wouldn't we would all be getting sick from our refrigerator filters and any other tap water filters we use around the house?

[steamman]

Keep in mind that water is the least expensive item in this hobby, so RO waste is a minimal cost. Add to that the fact that a 10 minutes shower uses more water than most units waste in a week and you can see how minimal the effect is of any conservation of the waste water.

The idea is great. But you can get better returns elsewhere in your home for less effort. Putting a flow restrictor on that shower for example. :)

Jeff

It is the cumulative impact on our water supply not what the individual dollar amount it cost us. If everyone recycled their waste water it would make a huge difference. One gallon at a time.
http://www.reefcentral.com/forums/showthread.php?t=1985475

[gods child]

reefsurfing got my vote.Use mine to water my gogeeberrys

[greenbean36191]

I know this will probably seem naive, but where is the bacteria coming from? Chlorinated water is relatively sterile going in, why would it carry bacteria with it?
The water going in is generally pretty clean, but it isn't sterile. You can find info about bacteria in your water from your utility's water report, though most only provide info on the percentage of samples that tested positive for coliforms (which is all they're required to report).

Neither the filters themselves or the housings are sterile though, and they, rather than the water, are one of the main sources of bacteria. When you change your filters next time, you'll notice that the insides of the housings are a bit slimy. That's a bacterial film.

If that were true then wouldn't we would all be getting sick from our refrigerator filters and any other tap water filters we use around the house?
No. First, most bacteria aren't going to make you sick, so even if you were drinking bacteria-laden water, you would be fine in most cases, and probably wouldn't even notice.

Second, an RO unit isn't really comparable to a faucet-mount or fridge filter. Faucet mounted and fridge filters remove the chlorine from the water right before it goes into your glass and you drink it. There's no time for any bacteria present to multiply in the water after it's been dechlorinated. On the other hand, everything between the carbon block and RO membrane in your RO unit is dechlorinated, but not sterile. When you aren't running the unit, the bacteria are sitting in a stagnant, nutrient-rich brine with nothing to keep them from multiplying. The Brita pitchers offer the best comparison since you have dechlorinated water sitting around for a while, but they're usually washed semi-regularly and kept near freezing in the fridge, which inhibits bacterial growth. As I learned in college, if you don't wash them for a while, they will indeed grow nasty things, even in the fridge. Even then though, you aren't passing the water through a filter that concentrates any waterborne bacteria right before you drink it as is the case when you're drinking RO wastewater.

While the risk of getting sick from drinking the brine is pretty small, a lot of people do get sick from drinking from poorly maintained RO and carbon filters around the house. A former member here, AZDesertrat, who worked in water treatment, has lots of horror stories about being called to people's houses to do bacterial testing because people were getting sick, only to find out that their tap water was just fine, but the water from their tap filter or RO unit that they were drinking or making ice with was off the charts because the filter wasn't properly maintained and sterilized.

If you read the literature that comes with RO units and replacement filters, almost every supplier recommends regular sterilization of the unit and provides instructions on how to do it, for precisely that reason.

Use the brine to rinse the dishes, water the plants, flush the toilets, do the laundry, mop the floor, etc. but I would avoid drinking it, especially if you haven't recently sterilized your RO unit. Either drink the chlorinated water or the output from the RO side.

[Agu]

I used RO/DI waste water to top off an outdoor fountain and had an issue with algae growth. Switched to tap water (with chloramine) and the problem went away.

Now I only use it to water plants or rinse equipment after cleaning my tanks.

[SaraB]

In the Spring, Summer and Fall I use it to top-off my Koi Pond and in the winter it hits the septic system. I figure the water has to be better than straight from the well at 450+ tds depending on the time of year!

[firebirdude]

I only have a nano tank. Used to use the waste water to fill the washing machine, but that got old. I dump it now.:hmm2:

[chicago_animal]

I was thinking of putting the "waste" in my 135G cichlid tank. The waste is better then the tap I was using, right?

[Randy Holmes-Farley]

I was thinking of putting the "waste" in my 135G cichlid tank. The waste is better then the tap I was using, right?

No, not necessarily.

RO waste water will have substantial ammonia in it if there is chloramine added to the water for treatment. Most anything else inorganic in it will be elevated by about 20% or so.

[Jamesurq]

I've got mine plumbed to my pool - I've only had the house for a single summer but I didnt' have to add any additional water from the tap for evaporation. That said, it was a pretty rainy summer.

Anyone with a well just plumb it back down the well? That's what I would do.