RO/DI wastewater idea....

mthedude · 11/22/2006, 08:35 AM

Might be a stupid idea and I didn't want to threadjack someone on a similar thread, so.......would it be possible to tap into your cold water feed and plumb in your RO wastewater line so that the pressurized running water going through the cold water feed would suck out your wastewater and thus feed it back into your RO? My thinking is that since there is some pressure on the wastewater line and it would basically be sitting right next to a fast moving water source, it wouldn't back siphon....or raw cold water shouldn't creep into the wastewater line. Make sense? It just seems that we're wasting perfectly good water that's been filtered by carbon, etc by just letting it run down the drain at a 3 to 1 ratio and it would make sense to use it somehow. I know a lot of people use it in thier washing machines, etc. but that won't work for me.

Would this idea work?

Keiths_Reefs · 11/22/2006, 09:26 AM

Are you saying feed the waste water back into your house's water supply? Unfortunately there's going to be more pressure coming from your house's water line than the waste water line. Unless you were using a booster pump on the RO/DI unit I'd think this would make it all come to a stand still.

mthedude · 11/22/2006, 09:39 AM

But wouldn't the more pressurized water draw the wastewater out of the RO unit faster? The same principal as when you put your car window down the air is sucked out of your car because the air outside is sucking it out?

fishysteve · 11/22/2006, 09:50 AM

Like an aspirator pump. I don't think it will work. You could use it to water some plants. Hydroponics maybe.

Keiths_Reefs · 11/22/2006, 09:52 AM

Maybe if you had a faucet on or something and had a venturi of sorts set up to draw the waste water line in it could work but under normal conditions your waterline is more like a balloon than driving through the open atmosphere.

AZDesertRat · 11/22/2006, 12:35 PM

The only way it can be done is with a booster pump to overcome the houses system pressure. Look up Watts Premier, they sell azero waste unit for just that purpos. It takes the waste through a booster pump and injects it into your hot water heater. Several disadvantages are it takes electricity to do this, it concentrates the TDS in your hot water so it defeats the purpose of a water softener and it is limited to about a 15 to 25 GPD unit or you run the risk of bursting pipes especially if you have a backflow device on your home and have no room for expansion.

vanmo92 · 11/22/2006, 02:12 PM

I doubt it would work. You dont want to put pressure on the waste line, I learned that the hard way, it just blows out the membrane.

monaca · 11/22/2006, 06:07 PM

AZDesertRat...you are the "Water Man"...( this and other RO/DI post)...my dad ran the "pump house" off of the Ohio river for our town back in the day... I loved hanging out their...great comments.

AZDesertRat · 11/22/2006, 06:17 PM

I guess after growing up along the Colorado River it kind of stuck with me. Its all I have ever done for over 33 years.

11/22/2006, 08:35 AM	#1
mthedude Registered Member Join Date: Sep 2004 Location: Des Moines, IA Posts: 549	RO/DI wastewater idea.... Might be a stupid idea and I didn't want to threadjack someone on a similar thread, so.......would it be possible to tap into your cold water feed and plumb in your RO wastewater line so that the pressurized running water going through the cold water feed would suck out your wastewater and thus feed it back into your RO? My thinking is that since there is some pressure on the wastewater line and it would basically be sitting right next to a fast moving water source, it wouldn't back siphon....or raw cold water shouldn't creep into the wastewater line. Make sense? It just seems that we're wasting perfectly good water that's been filtered by carbon, etc by just letting it run down the drain at a 3 to 1 ratio and it would make sense to use it somehow. I know a lot of people use it in thier washing machines, etc. but that won't work for me. Would this idea work? __________________ You........Cake or Death? I'll have the cake please.... ....well we're outta cake! Current Tank Info: 55g Reef Tank, scooter blenny, tail spot blenny, cleaner shrimp, button polyps, fuzzy mushrooms, hammer coral, multi color zoos, 10 gal fuge, Octopus NW150

11/22/2006, 09:39 AM	#3
mthedude Registered Member Join Date: Sep 2004 Location: Des Moines, IA Posts: 549	But wouldn't the more pressurized water draw the wastewater out of the RO unit faster? The same principal as when you put your car window down the air is sucked out of your car because the air outside is sucking it out? __________________ You........Cake or Death? I'll have the cake please.... ....well we're outta cake! Current Tank Info: 55g Reef Tank, scooter blenny, tail spot blenny, cleaner shrimp, button polyps, fuzzy mushrooms, hammer coral, multi color zoos, 10 gal fuge, Octopus NW150

11/22/2006, 09:50 AM	#4
fishysteve Registered Member Join Date: Jul 2004 Posts: 1,804	Like an aspirator pump. I don't think it will work. You could use it to water some plants. Hydroponics maybe. __________________ On a break

11/22/2006, 02:12 PM	#7
vanmo92 Registered Member Join Date: Aug 2005 Location: Silverthorne, CO. Posts: 2,045	I doubt it would work. You dont want to put pressure on the waste line, I learned that the hard way, it just blows out the membrane. __________________ PBITAWA Current Tank Info: 72 gallon bow Mixed Reef 1 fw tank

11/22/2006, 09:26 AM	#2
Keiths_Reefs Registered Member Join Date: May 2005 Location: Winnebago, IL Posts: 396	Are you saying feed the waste water back into your house's water supply? Unfortunately there's going to be more pressure coming from your house's water line than the waste water line. Unless you were using a booster pump on the RO/DI unit I'd think this would make it all come to a stand still.

11/22/2006, 09:52 AM	#5
Keiths_Reefs Registered Member Join Date: May 2005 Location: Winnebago, IL Posts: 396	Maybe if you had a faucet on or something and had a venturi of sorts set up to draw the waste water line in it could work but under normal conditions your waterline is more like a balloon than driving through the open atmosphere.

11/22/2006, 12:35 PM	#6
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	The only way it can be done is with a booster pump to overcome the houses system pressure. Look up Watts Premier, they sell azero waste unit for just that purpos. It takes the waste through a booster pump and injects it into your hot water heater. Several disadvantages are it takes electricity to do this, it concentrates the TDS in your hot water so it defeats the purpose of a water softener and it is limited to about a 15 to 25 GPD unit or you run the risk of bursting pipes especially if you have a backflow device on your home and have no room for expansion.

11/22/2006, 06:07 PM	#8
monaca Moved On Join Date: Nov 2006 Posts: 118	AZDesertRat...you are the "Water Man"...( this and other RO/DI post)...my dad ran the "pump house" off of the Ohio river for our town back in the day... I loved hanging out their...great comments.

11/22/2006, 06:17 PM	#9
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	I guess after growing up along the Colorado River it kind of stuck with me. Its all I have ever done for over 33 years.