Uses for RO reject water

[rmurken]

I can’t stand to let it run down the drain. Just can’t. Not in me. It’s perfectly good tapwater with no disinfectant and a somewhat more ions. Wouldn’t consume it, but seems like plenty to be done with it. To whit, things I have done:

1. Use for successive rinses of new GAC to get the dust out.

1a. Cleaning filter socks.

1b. Cleaning tank stuff generally. Today I mixed it up with some citric acid to get the coralline and other calcareous gunk off of various things.

2. Water the garden, water indoor plants.

3. Laundry—throw in clothes, a bucket or two of reject water, and set the machine to hot. Presto, warm water. Won’t work for front loader I guess. I also don’t do this if the bucket is dirty or the water is for whatever reason anything other than straight reject water.

4. Flush the toilet. This requires a certain compulsiveness, but this is reefing, where compulsiveness is a thing.

5. Add to RODI water to get to the target TDS for WC’s in my FW tank. Not a huge advantage over mixing tap, but the trip through the carbon stage does eliminate the need for dechlor. One less thing to add. (Yes I’ve checked for chlorine.)


Bonus: use old water from reef tank water changes to brine the sidewalk outside my house before a snow storm. Pavement has to be dry, and weather has to stay dry enough for the water to evaporate before the snow starts.

Bonus bonus: brining a turkey. Lol just kidding!

Anyone else share my insane inability to run good wastewater down the drain?

 

[AZMSGT]

Water Plants. Store greater amounts of RO water, this means you make it less often and create less waste.

 

[laverda]

Mine goes into two 60 gallom drums and I use it for most of the things you mentioned. There is no reason you can not drink it as well.

 

[redfishbluefish]

I use my waste water for doing wash. I collect in a 55 gallon drum that contains a MAG18 pump, and then have to trick my top loading washing machine to do the original fill of water. I also use it for the rinse cycle. That sliver of white in the lower left corner of this photo is the washing machine.

I also installed a sillcock (outside water faucet) so that I could pump the water outside to water the plants/lawn. But I found that the MAG18 wasn't strong enough to pump up that high....water just trickled out. You can see the hose going from the drum up to the sillcock.

 

[don_chuwish]

If I had a way to collect it then maybe I'd make better use. My reject line just goes out into the french drain around the house.

 

[rmurken]

Mine goes into two 60 gallom drums and I use it for most of the things you mentioned. There is no reason you can not drink it as well.

Agree it can be consumed, but (a) my wife and kids would not go along with that plan no matter how articulate and compelling my explanation; (b) would not amount to all that much—need higher-volume applications to use it efficiently.

I have seen seen concerns about fluoride being concentrated in reject water (no doubt it is), but I highly doubt it would be a health issue at the +25%ish concentration you’d get.

Maybe a slightly more practical problem is that reject water from a RODI system with a functioning carbon stage lacks any residual disinfectant. So you’d want to be at least be somewhat careful in terms of storage if you’re gonna drink it. Clean container, refrigeration I guess.

Final issue—you’d want to have comfort that you don’t have any lead issues. It’s highly unlikely—even if you have a lead service line or lead solder in your plumbing system. But if you were having a Flint-like problem where corrosion control was failing, it would compound the health risk. To be clear though, that would be highly, highly, HIGHLY atypical.

 

[rmurken]

I use my waste water for doing wash. I collect in a 55 gallon drum that contains a MAG18 pump, and then have to trick my top loading washing machine to do the original fill of water. I also use it for the rinse cycle. That sliver of white in the lower left corner of this photo is the washing machine.

I also installed a sillcock (outside water faucet) so that I could pump the water outside to water the plants/lawn. But I found that the MAG18 wasn't strong enough to pump up that high....water just trickled out. You can see the hose going from the drum up to the sillcock.

That is epic. Hats off to you for making it work! Our washer is on the first floor. Tank and RODI station are on the third. Don’t have it in me (and don’t have the space really—Philly twin home) to plumb a reservoir upstairs to the washer downstairs.

We do have a rain barrel, and it has occurred to me that when it gets low, I could just dump the water onto my second floor roof (from third floor), and it’ll just flow into the barrel.

 

[count krunk]

It waters the grass

 

[rmurken]

It waters the grass

I live in a twin in a city neighborhood. Basically no grass to water. But front and back gardens get a fair amount of reject water in the spring and summer, when things need to be watered around here.

 

[Daddy-o]

My reject goes into a brute that is curing a ton of home made frag discs. I have the barrel elevated with a spiquet on the bottom. When it gets full, I water the garden and then the barrel refills and continues to cure my discs.

 

[ZoWhat]

Maybe we can do a Cooperative and pipeline everyone together

 

[Fishingandreefing]

Straight to the drain! Each week I make about 50g rodi so that’s roughly 250g of tap. So it’s about $2 if that?

 

[rmurken]

Straight to the drain! Each week I make about 50g rodi so that’s roughly 250g of tap. So it’s about $2 if that?

Truth. Water is cheap. It’s the principle of it though. Also, I use about 15% the volume you do, so it’s usually practical for me to find uses for the quantity of reject water I accumulate. In your case...dunno what you’d do with 200G of water/week unless you were into serious agriculture.

 

[Fishingandreefing]

Truth. Water is cheap. It’s the principle of it though. Also, I use about 15% the volume you do, so it’s usually practical for me to find uses for the quantity of reject water I accumulate. In your case...dunno what you’d do with 200G of water/week unless you were into serious agriculture.

I partially agree with you. I used to think like that but it’s just too much hassles and time consuming to save couple of dollars while you have family and other stuffs to handle.
Waste water goes down to the drain and it gets recycle so I just let it be. Out of sight out of mind.

 

[rmurken]

I partially agree with you. I used to think like that but it’s just too much hassles and time consuming to save couple of dollars while you have family and other stuffs to handle.
Waste water goes down to the drain and it gets recycle so I just let it be. Out of sight out of mind.

Legit.

I wonder if there are cichlids that would like reject water.

 

[Fishingandreefing]

Legit.

I wonder if there are cichlids that would like reject water.

Why would cichlids like waste water?

 

[rmurken]

Why would cichlids like waste water?

Minerals.

 

[laverda]

Agree it can be consumed, but (a) my wife and kids would not go along with that plan no matter how articulate and compelling my explanation; (b) would not amount to all that much—need higher-volume applications to use it efficiently.

I have seen seen concerns about fluoride being concentrated in reject water (no doubt it is), but I highly doubt it would be a health issue at the +25%ish concentration you’d get.

Maybe a slightly more practical problem is that reject water from a RODI system with a functioning carbon stage lacks any residual disinfectant. So you’d want to be at least be somewhat careful in terms of storage if you’re gonna drink it. Clean container, refrigeration I guess.

Final issue—you’d want to have comfort that you don’t have any lead issues. It’s highly unlikely—even if you have a lead service line or lead solder in your plumbing system. But if you were having a Flint-like problem where corrosion control was failing, it would compound the health risk. To be clear though, that would be highly, highly, HIGHLY atypical.

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.

 

[fish farmer]

Summertime it goes into a rain barrel, winter it goes down a drain into the yard.

I do have a barrel inside for some bypass water which I use for indoor plants or rinsing buckets.

 

[Hilltopreef]

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.