Throwing Away RO/DI Waste Water??

[cliscum]

I set up my RO/DI unit last night to begin filling my aquarium. Immediately I was concerned with how wasteful the system was. Mine appears to dispose of 3 gallons of water for each gallon produced. My TDS in is ~70, my TDS out is ~0, and the waste water TDS is ~95.

With a 75 GPD unit, I would be disposing of 225g of water a day at full tilt.

Has anyone developed a system to use this water in a meaningful way?

-Charles

 

[rickey]

Abuddy of mine in FL has his going to a storage tank in the yard that he uses to help fill his pool and water his gardens; not that this will do all of that. His gutters also contribute greatly to this cause.

Another friend of mine in SC has his routed through the walls outside to his flower beds.

 

[hellfire]

I read a while ago that someone had his routed into his Laundry Room to wash clothes.

Tyler

 

[gwhiz]

Mine routs into flowerbeds outside...

 

[mojo]

It's unlikely you'll actually get 75gpd out of a 75gpd unit without taking some extra steps. However, what you're experiencing is pretty typical- I've heard of everything from using the water for laundry to watering plants. Just remember that it has been stripped of chlorine, so bacteria can grow in it - you'd be safe to use it in any grey-water system, but be careful using it in a potable system.

You can increase the efficiency of your RO unit if you're willing to spend some money. I have two membranes (the waste from the first feeds the second) and a pressure pump pushing the membranes to 85 psi, and finally a second restrictor on the waste. I get about 3 gallons of RO to every 1 waste, and can make almost 200gpd out of my two 75gpd RO filters. It's a bit more complex (and expensive) than a standard setup, but when I started getting $120/mo water bills, it didn't take long to pay for itself....

 

[jhutto]

did you buy the one the filter guys have as they do the same thing? At least that is what it appears from their website.

 

[mojo]

Nah - I already had a Kent unit from long ago, but I did upgrade it with parts from their website.

 

[cliscum]

mojo;266159 wrote: It's unlikely you'll actually get 75gpd out of a 75gpd unit without taking some extra steps. However, what you're experiencing is pretty typical- I've heard of everything from using the water for laundry to watering plants. Just remember that it has been stripped of chlorine, so bacteria can grow in it - you'd be safe to use it in any grey-water system, but be careful using it in a potable system.

You can increase the efficiency of your RO unit if you're willing to spend some money. I have two membranes (the waste from the first feeds the second) and a pressure pump pushing the membranes to 85 psi, and finally a second restrictor on the waste. I get about 3 gallons of RO to every 1 waste, and can make almost 200gpd out of my two 75gpd RO filters. It's a bit more complex (and expensive) than a standard setup, but when I started getting $120/mo water bills, it didn't take long to pay for itself....

I will be doing this mod in the near future. The water pressure to my house is near 100psi. I have access to this full pressure and reduced pressure in the house.

Overall I am pleased to have 0 tds water for myself and my aquarium. I was hoping to share this with anyone in my area for free, but the amount of waste water being produced is unacceptable for the moment.

I will start a build thread soon, as of now I only have a 24g aquapod that is to become my QT.

-Charles

 

[mojo]

If you're water pressure is already 100psi from the tap, then I'd recommend getting a couple more membranes, and just letting it do it's thing. The other thing you can do to really increase efficiency (though sacrificing a small bit of life off the membranes) is to get a needle valve (

 

[gwhiz]

mojo;266159 wrote: You can increase the efficiency of your RO unit if you're willing to spend some money. I have two membranes (the waste from the first feeds the second) and a pressure pump pushing the membranes to 85 psi, and finally a second restrictor on the waste. I get about 3 gallons of RO to every 1 waste, and can make almost 200gpd out of my two 75gpd RO filters. It's a bit more complex (and expensive) than a standard setup, but when I started getting $120/mo water bills, it didn't take long to pay for itself....

I wasn't aware that this was an option--thanks Chris! I gotta go check my water pressure!

 

[mojo]

No problem. Take a look at

 

[jayguerreso]

Can always donate the water to us non Ro uniters.. =)

 

[gwhiz]

jayguerreso;268924 wrote: Can always donate the water to us non Ro uniters.. =)

No problem! I'm buying another membrane (my water tested at 95 psi at the tap) you can come down and pick up my waste water. It'll have about 4 times the TDS of what your water has from the tap, but it's all yours!

BTW--if you're on city water, there's probably a pressure regulator where the water enters your house....it may be possible to increase the water pressure in your house by adjusting the regulator. I'm sure that there are plumbers in the crowd that will tell us why this is a bad idea, but....

 

[cliscum]

Gwhiz;268976 wrote: No problem! I'm buying another membrane (my water tested at 95 psi at the tap) you can come down and pick up my waste water. It'll have about 4 times the TDS of what your water has from the tap, but it's all yours!

BTW--if you're on city water, there's probably a pressure regulator where the water enters your house....it may be possible to increase the water pressure in your house by adjusting the regulator. I'm sure that there are plumbers in the crowd that will tell us why this is a bad idea, but....

Gwhiz- 95 psi at tap! Sounds like the water pressure in your house is to high and should be reduced. The pressure that I have available at 110 is for my sprinkler system and outdoor hoses, and I regulate that to 80 psi.

Cranking up the water pressure in the house has its advantages... Nice shower massage, better RO/DI production, flooded basement...

Unless you have a super attractive insurance agent , I would advise against it.

-Charles

 

[gwhiz]

Cliscum;269024 wrote: Gwhiz- 95 psi at tap! Sounds like the water pressure in your house is to high and should be reduced. The pressure that I have available at 110 is for my sprinkler system and outdoor hoses, and I regulate that to 80 psi.

Cranking up the water pressure in the house has its advantages... Nice shower massage, better RO/DI production, flooded basement...

Unless you have a super attractive insurance agent , I would advise against it.

-Charles

Yea...it was a bit higher than I thought it was. I was surprised when I tested it last night--it certainly doesn't feel that high. I'm gonna crank it down a bit...

 

[cliscum]

I keep my internal pressure at 65. Looks like anything under 80 is fine.

http://answers.google.com/answers/threadview?id=253486">http://answers.google.com/answers/threadview?id=253486</a>

This is an interesting service I have been shown. People ask questions and post a dollar amount, the best answer receives the money. The answer to this question got 3.50.

-Charles