RODI -go green! no more waste water!

Green? If you live in a part of the country that has hard water (~400ppm here), but which has plenty of it (like we do here - no shortage here, like in other parts of the country), then this is not a very green idea at all.

Here, a DI cartridge without RO will last 50-100 gallons. So let's assume 100. Let's also assume that the RO unit will consume 3x that amount.

So, with this idea I could either spend a little extra on electricity to pump an additional 200 gallons of water from the ground (my household of 5 consumes about 1000 gallons of water a week, excluding the tank - 200 gallons is really not very much), or I could spend energy on the manufacture, transport, and transport and disposal of waste for the DI resin.

I'll stick with my RO unit.

For those that live somewhere with very soft water (where DI resin alone might last a while) and that is (very) short on fresh water this might make more sense, but if a full lifecycle energy analysis is done, I have my doubts that it could still be considered "green".
 
one of the lfs here in cuse used to sell di water and they had a huge tank hooked up to a hose 100% of water that went in came out the other end and they made plenty . it came as a from a water company here in cuse and they had to replace the entire unit once a month at a cost of $70 .they supplied 100s of gallons and sold it to customers too. i tested some of it and it was 0tds but i never tested it for anything else . the lfs went out of business but they never had any complaints and their tanks were cleanish with no algae outbreaks ,they just didnt maintain them enough but IMO they may have been on to something . the unit was the size of a large welding container ,it was a cylinder that was 12"across tube and it was 4 1/2 feet tall . it weighed 70 or 80 lbs . it was strictly di resin and you could fill your tub in 10 minutes easily .
 
i live in the pine barrens in south jersey and water cant get much softer than mine (its mildly acidic i think my water test showed the ph in the low 5s) it eats copper pipes fast. i also have very low tds less than 50 coming in but the co2 in the water eats my di resin fast. i only have 2 tds out of my ro membrane but i can kill a di canister in less than 50 gallons of water. i put my waste water into a dry well that my sump pump goes to so it makes its way back to the water supply.
 
Finchie said:
get rid of your RO and double up your DI, the little bit of extra money you have to pay for replacing your DI more often is worth all the hassle and makes up for your water bill anyways.
Click to expand...

if you do the math, waste water costs is minimal. in my case, it is less than $1 a month.

my water rate is $1.62 per hundred cubic foot, or 748 gallons and my waste water is way less than that.

so you will spend more money without the RO membrane. but if this is done for philosophical reasons, then it is priceless.

no RO membrane does saves time though, but with patience being promoted left and right in this hobby, that includes patience waiting for your RODI container to fill up.
 
funny cause the lfs here in cuse never had algae issues but i just never believed that their water was "clean" and now i know it probably was and yes it can be done easily with no wasted water .~pretty cool IMO !
 
Can't do this for Oklahoma City water then. We have one of the highest phosphate and hard water levels. We have to add another Phosphate filter addition to our RO/DI units to get our phosphates to zero.
 
^ Really? you could actually post something you know ...usefull.. before worry about counting other ppls posts. I was away from Rc for awhile.


Very Good thoughts and insights everybody. In response to all the posts about which is greener Ro or DI. I dont think there is an answer for this question, and that's not what this thread was intended for:spin1:. Sure does make out for a good conversation though doesn't it? Obviously there is way too many conflicting factors to take into consideration about your own source water to determine an accurate answer. For some of us a DI setup will most certainly be the "œgreen" way to go and way more cost effective, but lets not get these two confused. The cheapest way to get what you want usually isn't always the most environmentally freindy, seems it just doesn't work out that way.

I think alot of you need to visit a water treatment plant like I had to for a class in college. You will be amazed and realize all the energy and resources it takes to run one. Just because you have a cheap water and sewage bill doesn't make it ok to dump all that perfectly good RO waste water down the drain , this cant be a good thing from a "œgreen" perspective. Also I think those complaining about the manufacture, transport and disposal of waste for the DI resin. Need to take into consideration that RO filters also have to be manufactured, transported and disposed of and end up in the same land fills as the Di resin. Considering the fact that the DI resin helps keep waste water minimal may possibly offset the differences of it and RO filters making them equally efficient or "œgreen" .

For those interested in a Di system, if you dont have high Co2 levels and or a very hard source water then a Di system like mine should seriously be considered. Not to mention if you have a septic tank or expensive water bill in general then a 0 waste water setup could be your best friend.

I will make a diagram eventaully.
 
Fwiw, I've run a Kold-Steril water filter for about the last 8 or 9 years. My source water as Finchie hints, doesn't have many issues to begin with and it's worked perfectly in my case. Our community well sits way up high, and between a National Park, and a large State Forest in N.E. Pa. When I first tried RO years ago, the waste to RO ratio was 12 to 1 in winter. Yes the water gets REALLY cold in the pipes. No waste water whatsoever. It surely won't work for all water sources, but as in my case, it might work for some.
 
coralnut99 said:
Fwiw, I've run a Kold-Steril water filter for about the last 8 or 9 years. My source water as Finchie hints, doesn't have many issues to begin with and it's worked perfectly in my case. Our community well sits way up high, and between a National Park, and a large State Forest in N.E. Pa. When I first tried RO years ago, the waste to RO ratio was 12 to 1 in winter. Yes the water gets REALLY cold in the pipes. No waste water whatsoever. It surely won't work for all water sources, but as in my case, it might work for some.
Click to expand...

With cold tap water, you should just adjust the $4 flow restrictor to get yourself back near a 4:1 ratio.

Russ
 
We've set up DI only systems for many customers over the years. Those kati/ani systems from europe are nothing more than a separate bed di system.

If you are going to go this route, remember that the ratio of anion resin to cation resin should be 1.5:1, and you should have your filters in this order:
Sediment filter (s)-> carbon block-> cation resin -> anion resin

Russ
 
Waste water ????
Its only waste water if you let it go down the drain. lazy :thumbdown
 
Shoot. I use my wastewater to help top off my rainwater collector barrels. I use those with a pump and hose to water my lawn. I talk about it a little in My tank build thread.

Get greener than me! I dare you :)
 
acropora1981 said:
Please clarify this. This interests me; as a Canadian. Could I use a little ball valve?
Click to expand...

Let's say you have a 75 gpd membrane. During winter, you could go with a 50 gpd capillary restrictor, and trim it shorter if needed to get to a 4 to 1. Because nearly all of the restriction occurs in about 1/4 of the motion of a ball valve, they aren't a good choice. An adjustable restrictor/needle valve is an option:

NeedleValve.gif


Russ
 
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