RO system waste water

[pretzelb]

Living in Texas we are seeing more and more water restrictions so when shopping a home RO system the thought of a 1 to 4 ratio has me second guessing. Anyone care to share how they bring that ratio down or ways they capture that waste water? I can't picture running the water to my irrigation system or even to my washer. And that 1 to 4 ratio make me cringe.

 

[LandoLincoln]

Living in Texas we are seeing more and more water restrictions so when shopping a home RO system the thought of a 1 to 4 ratio has me second guessing. Anyone care to share how they bring that ratio down or ways they capture that waste water? I can't picture running the water to my irrigation system or even to my washer. And that 1 to 4 ratio make me cringe.

Yeah, you could capture the waste water for other things. But on a homebrew scale...it's really not going to add up to much.

 

[Yooper]

I have used the waste water for the washing machine (just by switching the hose to the machine), watering plants, and so on. I don't know of all the systems out there, but mine is probably more like 1:5 or 6, rather than 1:4 rejection rate. I have also saved some in a bit trash can for using for cleaning up my brew gear, but that was a big pain. Of course, we don't have water restrictions or concerns where we live, so I didn't really put much of an effort into it like I could have.

I do 10 gallon batches, so I start with 15 gallons of water in a batch, which means a lot of waste water for sure.

 

[pretzelb]

I plan to start 10g batches soon so it could add up. If I installed it by our utility sink in the garage there isn't really a way to physically pipe the water somewhere useful. I guess I could install a switch and either have it run down the drain or run into a bucket where I could then use it anyway I want. I'm definitely not storing buckets of water in the garage.

I think we'd use this for drinking water daily if we had it installed so it would be useful for more than brewing. I'm actually interested to see what it would do to my home roasted coffee.

 

[Buckeye_Hydro]

YOU control the ratio of waste water to purified water with a small little part called the "flow restrictor." If you are much above a 4:1 in most applications you are needlessly wasting water.

Russ

 

[pretzelb]

YOU control the ratio of waste water to purified water with a small little part called the "flow restrictor." If you are much above a 4:1 in most applications you are needlessly wasting water.

Russ

What would be the best you can hope for in a ratio? And what do you risk or lose as you try to get a better ratio on waste?

 

[Buckeye_Hydro]

It really depends upon your water quality. We have some customers with tap water TDS <30 ppm. It's almost RO water quality. These people can get away with all sorts of things that others can't. We have another customer with well water at 2,400 ppm. Yes - 2,400. No way he should try additional restriction.

Do you have a residential scale system? If so, and if you don't have a good water analysis, and if that data hasn't been fed into a model for the purpose, the cost of experimenting a bit is not too awful high. A new 75 gpd membrane can be had for less than $40. 15 years ago it was $100.

"Waste water," otherwise known as "concentrate," should be thought of as "flush water." It's this water that rinses out all the contaminants that don't make it through to the good water ("permeate") side of the membrane. If you restrict the flush water too much, you'll get certain contaminants building up inside the membrane, and you'll essentially plug ("scale" or "foul") the membrane.

Russ

 

[pretzelb]

I finally found my report from Ward and the TDS was 289.

Either I need to search more to get ideas on what can be done to preserve that waste, or I need to pick the brain of a local plumber who had installed a few.

 

[Buckeye_Hydro]

That would be us. Pick away.
Russ