Uses for RO reject water

[rmurken]

Water going down the drain is not wasted. The affluent would be good to water the plants with to save you some electricity or on your water bill but every drop going down the except what the plants use ends up back in the ocean through evaporation from your drain field or the sewer plant. It’s called the Hydrologic system. My RO is outside my home feeding into a 55 gallon drum. The affluent waters the grass and shrubs.

I understand the water cycle. The waste is three things: (1) production of water by the utility (intake, treatment, storage, pumping); (2) my water bill; (3) processing of effluent as sewage.

None of these things are particularly significant, even taken together, possibly even multiplied cross the hobby. But I still feel compelled to minimize the waste. No judgment on anyone who runs it down the drain. There are far bigger things to worry about.

Also, I live in Philly where the water supply is copious, cheap, and robust. I once read about a reefer in a remote area whose water supply was trucked in. That individual had to make the most of every gallon, including effluent. Different strokes for different folks.

 

[rmurken]

I wouldn’t be

You waste is cleaner than tap. I don't know what stage of a RO/DI specificly removes fluoride or lead. The first stage removes some metals, which is why they get rust colored sometimes. The second stage removes a lot of toxic chemicals. It typically removes between 60-80 chemicals, including 14 most common pesticides and partially removes another 30 chemicals. This makes it much safer than tap water or the water out of a typical refrigerator filter. Here is a link about carbon filtration. What carbon filters remove.
The RO removes mostly calcium, alkalinity, magnesium and other very small minerals.

Thanks for that link. I am under the impression that the first stage is typically sediment, and doesn’t reduce TDS, but instead would trap anything that is particulate—for instance, minute amounts of rust.

I am not certain whether a a typical RO carbon stage would remove metals. I always assumed (emphasis on assumed—have not researched) that they were designed to dechlorinate the water before it goes to the chlorine-sensitive membrane. Carbon removes a lot of stuff though, and exactly what depends on what type of carbon is in use.

Things that are dissolved, like metal ions, I think of as TDS that the RO membrane filters out...and washes away in effluent. So my assumption has always been that IF there were lead, it would make it past the sediment and carbon stages and get filtered out in the RO and DI stages.

But I wrote my last response late last night, and tbh the lead thing is wildly unlikely in a modern water supply. Notwithstanding the horror in Flint.

So I agree with you: it’s totally drinkable!

 

[robbyg]

Mine waters my wifes garden.
I bought two lengths of 1/2" PVC and a few elbows and a bung. I drilled some very tiny holes in the PVC at points where the Plants are. I ran the PVC in the flower bed and just stuck the Ro waste hose into the PVC. It kind of acts like a soak away system. I can definitely tell that it works because the Plants are looking much better now then when they had to depend on our sporadic watering.

 

[Krw]

Goes into my people aquarium,

 

[BobT]

plant watering, car washing, fish stuff cleaning,

 

[BeSaltyReefer]

Goes to the pond and duck pond, main vegetables garden during the season, fills up goat, chicken, and dog water dishes, all house plants etc. I am a well and septic so I also feel somewhat compelled to use it plus I don't want to just fill my septic tank.

 

[grobp67]

Fills my pool.

 

[rmurken]

Goes to the pond and duck pond, main vegetables garden during the season, fills up goat, chicken, and dog water dishes, all house plants etc. I am a well and septic so I also feel somewhat compelled to use it plus I don't want to just fill my septic tank.

Yeah, that makes sense too.

 

[rmurken]

Fills my pool.

We live on a tiny parcel...no way we could have a pool...but if my kids were still young enough for kiddy pools, would be a great use for it.