ro water saving idea
- Thread starter little_squid
- Start date
Back to the thread. In all honesty everyone........I bought a RO/DI unit from fahz and I am very happy with how it came packaged. I am pleased with how it performs. And the price was awsome. I would have paid $150.00 more for this unit through anywhere else.
So whatever he says, believe that he experimented with it first.
So whatever he says, believe that he experimented with it first.
fahz
Premium Member
Savatage here are the test results for 85 psi at the first membrane. Everything is well within FilmTec membrane operating conditions for both mrembranes.
Jim
TAP WATER TDS 66
TAP WATER TEMP 65 DEGREES
AQUATEC 8800 BOOSTER PUMP
PSI AT FIRST MEMBRANE 85 PSI
TIME TO PRODUCE 1 GALLON 8.45 MINUTES
WASTE WATER 5.7 QUARTS
PRESSURE DROP BETWEEN MEMBRANES 2 PSI
PRODUCTION WATER 7.1 GPH 170 GPD
WASTE WATER 10.1 GPH 242 GPD
GALLONS OF WATER SAVED 438 GPD
Jim
TAP WATER TDS 66
TAP WATER TEMP 65 DEGREES
AQUATEC 8800 BOOSTER PUMP
PSI AT FIRST MEMBRANE 85 PSI
TIME TO PRODUCE 1 GALLON 8.45 MINUTES
WASTE WATER 5.7 QUARTS
PRESSURE DROP BETWEEN MEMBRANES 2 PSI
PRODUCTION WATER 7.1 GPH 170 GPD
WASTE WATER 10.1 GPH 242 GPD
GALLONS OF WATER SAVED 438 GPD
Roland Jacques
Premium Member
I think we covered about all the info needed to make this miser RO system. But I do have 2 more questions. I decided to stick with building the 3 membrane in series set-up, I will add a booster later if I have too. I anticipate flowing no more than 25 gallons per hour up to the first membrane. 1/4" RO hose ID is .170". How much flow can go though that small of a hose at the various psi's? (40, 50, 60, 70, 80,) Is their a chart anywhere?
On a lower pressure system I think this could make deference. I think I should be using 3/8" tube because it has 2.50" id. At least up to the first membrane but without a chart im just guessing.
I want to know the pressure drop and TDS reading between each filter and membrane on my system. But that is a lot of gauges and meters. 14 deferent $pot$. Instead of buying 14 deferent gauges and 7 dual meters. I plain to build a manifold with isolation valves hooked to 1 gauge and TDS meter. I think my measurements will also be more accurate because I would be using only 1 common gauge and TDS meter. The manifold would have a drain to get flow for the TDS reading and to drain pressure between pressure readings. Do you think this should be good?
On a lower pressure system I think this could make deference. I think I should be using 3/8" tube because it has 2.50" id. At least up to the first membrane but without a chart im just guessing.
I want to know the pressure drop and TDS reading between each filter and membrane on my system. But that is a lot of gauges and meters. 14 deferent $pot$. Instead of buying 14 deferent gauges and 7 dual meters. I plain to build a manifold with isolation valves hooked to 1 gauge and TDS meter. I think my measurements will also be more accurate because I would be using only 1 common gauge and TDS meter. The manifold would have a drain to get flow for the TDS reading and to drain pressure between pressure readings. Do you think this should be good?
fahz
Premium Member
Here are some things to ponder. Membrane housing fittings are 1/8 x 1/4 for standard housings. 75 GPD Filmtec membranes can handle 2 GPM flow rate. I'm not sure what the flow capacity for a 1/8 fitting is but I'm sure we can find out. In the testing I did, the pressure drop between membrane one and two was 2 psi. I experienced a 4 psi pressure drop in the three stage sediment carbon filter stages. We have no sediment load in our municipal water system so sediment loading is not a factor. But one of the factors may be I'm using a 12 x 40 mesh chloramine granular activated carbon filter in the second stage.
How much water do you need to produce in a day or in an hour a factor?
Jim
How much water do you need to produce in a day or in an hour a factor?
Jim
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BeanAnimal
Premium Member
Why bother with all the trouble. Use a single john guest tee and gauge. All you need to do is take the pressure readings once at your desired input pressure.
You also have no use for all of those TDS meters. You can gauge the performacne of the system with MATH and the output of the first membrane. Also, INLINE meters are pretty much useless, esp in the pricerange that is available to this hobby. A good handheld unit is many times more reliable.... so put a tee and valve in a few spots if you really want to read the TDS in different parts of the system.
Spending $200 on fittings and manifolds, housings, and two extra membranes is certainly going to take a long time to pay off in terms of waste water. A LONG LONG TIME
You also have no use for all of those TDS meters. You can gauge the performacne of the system with MATH and the output of the first membrane. Also, INLINE meters are pretty much useless, esp in the pricerange that is available to this hobby. A good handheld unit is many times more reliable.... so put a tee and valve in a few spots if you really want to read the TDS in different parts of the system.
Spending $200 on fittings and manifolds, housings, and two extra membranes is certainly going to take a long time to pay off in terms of waste water. A LONG LONG TIME
jdieck
New member
I think the issue is to avoid water waste rather than pay back of the extra membrane.
A second 75gpd membrane will save about 2 gallons of waste per gallon of produced water.
Assuming the cost of water to be (as in my case) 0.5 cents per gallon the savings will be one cent per gallon of product water. Assuming the cost of a second membrane to be $75.00 you will need to produce 7,500 gallons of product water to break even.
In other words a heavy user like myself with 55 gal per week will need 136 weeks (roughtly 11 years!) to pay it back
But again the benefit is saving water plus of cource doubling the system capacity. In my case filling a 55 gal container after a water change in just 9 hours rather than 18 hours. This has been very convenient for me as I travel a lot and always leave a full drum of mixed water for emergencies when I leave. I change water Sunday morning, and by the end of the day I have a new drum ready with newly mixed water before I leave on Monday.
fahz
Premium Member
In areas of the country where there are water shortages and restricted usage cutting the waste water really makes sense. If your using large amounts of water a 4:1 waste is big, but 1 1/4:1 and you can find a us for the waste water. Considering what we spend in this hobby the cost of a conversion kit is nothing.
Jim
Jim
I do not agree with this statement at all. Consider this for a factor. Where I am from we have to pay for water in this way.
--We pay for each Gallon of USE.
--We pay for each Gallon of Waste, which is Sewer Use.
--We pay for each Gallon for Drainage, which is factored as part of rain runoff. (don't ask, because I don't even understand it.)
--We also pay a Service fee for the meter reading (even though the meters have transmitters on them and no-one ever comes to look at the readings.)
When you add all of these extra costs up per Gallon. It definately saves me money. If I buy another RO Membraine for 60.00, it will pay for itself in one or two billing periods.
BeanAnimal
Premium Member
This is going to be long.... but I think it (the cost and motivations/rewards) needs addressed before misconceptions run rampant.
The fact is that most of that post (my previous) was directed towards the "manifold" and extra instruments proposed to determine what is going on in every stage of the system. When in fact these devices [RO/DI units] are very simple. As long as each component is working as expected, simple math will get you close to determining the service life of each component. Simple placement of a single gauge and TDS readings will help to setup the system to get a "baseline" of what is expected and tweak anything that needs tweaking. From that point standard spot checks are enough to determine if they system is functioning in the expected way. Using all the extra parts and components is [pun] pouring money down the drain.
With regards to the "cost saving", those have already been briefly outlined by jdieck [but I will trudge through it again]. As a matter of fact, most of us now pay the meter fees, sewage based on consumtion... etc. This has NOTHING to do with consumption or cost saving whatsover in 99.9% of residential situations. THEY ARE FIXED FEES. The fact simple fact is that the COST will likely never be recouped in a project like this (not a bad thing, just a reality). If you are really interested in saving money, there are much better ways to go about it.
With regards to the environmental aspect.... points could be made on both sides. Water down the drain is not "water wasted" per say. This of course depends on the area, watershed and a lot of other factors. In any case, your COST takes this into consideration and again will likely never exceede the cost of the extra components. We can leave the environmental debate the ther tree huggers and clear cutters. IF that is your motive (tree hugging) then enjoy and feel good about your contribution.
This leaves us whith your statements and somewhat uninfromed opinion (not a bad opinion, just not well thought out). You can certainly disagree, but please do put some math with your statements to back them up.
If you can show me $60 worth of wastewater I will honestly be amazed. But as far as I can tell from your water authority website and their rate schedule at:
http://www.ci.wausau.wi.us/is/utl/pdf/Rateschedule030106.pdf
You pay $1.64 for every every 748.05 gallons (100 cubic feet). You also pay about $1.88 in sewage fees per every 748.05 gallons consumed. However you pay the usage from the LEAST quarter. We will use WORST CASE to make it easy (that is 1 gallon of sewage charged per 1 gallon used). The meter/fire costs HAVE NOTHING to do with the savings, you pay those even if you don't use a drop of water.... so talking about them further is pointless. Remember in reality you pay sewage based upon the lowest quarter (the winter for most people) and the sewage costs will on avg be about 30% less (no water the lawn, filling the pool, washing the car, less showers, etc).
So you pay $3.52 per 748.05 Gallons. That is $ 0.47 per 100 gallons or .0047 cents per gallon (pretty damned cheap water compared to here).
Lets say you make 25 gallons of RO/DI a Day. That is 100 Gallons of waste at 1:4. OR .47 cents a day. Your one month cost would be about $14 down the drain in waste water. Using the second RO membrane would cut that to around $7 a month down the drain. So even at a whopping usage of 25 RO/DI gallons a day, it would take you 11 months to break even on the investment! AND THAT IS IF THE UPGRADE REALLY ONLY COSTS $75.
Now back to reality and the fact that you likely make an average of 5 gallons per day (20 gallons waste)... and your sewage cost os closer to $1 per 100 gallons. that puts the payoff at least 5 years down the road (and closer to 6-7 in reality). BUT WAIT!!! You need to buy 2 membranes instead of one every several years. This puts the payoff even further out.
Honestly... if you want to take the environmental postion, I will understand and even agree with many of the points... but the "cost savings" arguement is never going to get any traction.
As a side note:
You may also want to look into the fact that I live in Pittsburgh PA and pay THE HIGHEST (or second highest last time I looked) PER GALLON COST In the entire COUNTRY! Yes you read the correctly, the most expensive water in the entire country. The funniest part is that our water comes from the Three Rivers and there is no such thing as a water shortage or water storage. The water costs VERY LITTLE to treat and we don't have to re-treat the sewage and produce drinking water. If WE have a water shortage, it means that the Monongahela, Ohio AND Allegheny rivers have dropped at least 10 feet below NAVIGABLE stage. (the water level is controlled by the ARMY CORE OF ENGINEERS). If the rivers drop that low, rest assured that the entire east coast will have LONG been without ANY water and all commerce on the east coast will have long before ground to a halt. You may also find it funny that when other parts of the state are put on a water restriction, we are as well. The honest answer from the numbskulls in Harrisburgh is that [SIC] "It is the fair thing to do!, why should some people of the commonwealth be forced to ration and others not!". When put on the spot, they sidestep the facts and resort to PC spin. Gotta love elected and appointed morons.
Enjoy
The fact is that most of that post (my previous) was directed towards the "manifold" and extra instruments proposed to determine what is going on in every stage of the system. When in fact these devices [RO/DI units] are very simple. As long as each component is working as expected, simple math will get you close to determining the service life of each component. Simple placement of a single gauge and TDS readings will help to setup the system to get a "baseline" of what is expected and tweak anything that needs tweaking. From that point standard spot checks are enough to determine if they system is functioning in the expected way. Using all the extra parts and components is [pun] pouring money down the drain.
With regards to the "cost saving", those have already been briefly outlined by jdieck [but I will trudge through it again]. As a matter of fact, most of us now pay the meter fees, sewage based on consumtion... etc. This has NOTHING to do with consumption or cost saving whatsover in 99.9% of residential situations. THEY ARE FIXED FEES. The fact simple fact is that the COST will likely never be recouped in a project like this (not a bad thing, just a reality). If you are really interested in saving money, there are much better ways to go about it.
With regards to the environmental aspect.... points could be made on both sides. Water down the drain is not "water wasted" per say. This of course depends on the area, watershed and a lot of other factors. In any case, your COST takes this into consideration and again will likely never exceede the cost of the extra components. We can leave the environmental debate the ther tree huggers and clear cutters. IF that is your motive (tree hugging) then enjoy and feel good about your contribution.
This leaves us whith your statements and somewhat uninfromed opinion (not a bad opinion, just not well thought out). You can certainly disagree, but please do put some math with your statements to back them up.
If you can show me $60 worth of wastewater I will honestly be amazed. But as far as I can tell from your water authority website and their rate schedule at:
http://www.ci.wausau.wi.us/is/utl/pdf/Rateschedule030106.pdf
You pay $1.64 for every every 748.05 gallons (100 cubic feet). You also pay about $1.88 in sewage fees per every 748.05 gallons consumed. However you pay the usage from the LEAST quarter. We will use WORST CASE to make it easy (that is 1 gallon of sewage charged per 1 gallon used). The meter/fire costs HAVE NOTHING to do with the savings, you pay those even if you don't use a drop of water.... so talking about them further is pointless. Remember in reality you pay sewage based upon the lowest quarter (the winter for most people) and the sewage costs will on avg be about 30% less (no water the lawn, filling the pool, washing the car, less showers, etc).
So you pay $3.52 per 748.05 Gallons. That is $ 0.47 per 100 gallons or .0047 cents per gallon (pretty damned cheap water compared to here).
Lets say you make 25 gallons of RO/DI a Day. That is 100 Gallons of waste at 1:4. OR .47 cents a day. Your one month cost would be about $14 down the drain in waste water. Using the second RO membrane would cut that to around $7 a month down the drain. So even at a whopping usage of 25 RO/DI gallons a day, it would take you 11 months to break even on the investment! AND THAT IS IF THE UPGRADE REALLY ONLY COSTS $75.
Now back to reality and the fact that you likely make an average of 5 gallons per day (20 gallons waste)... and your sewage cost os closer to $1 per 100 gallons. that puts the payoff at least 5 years down the road (and closer to 6-7 in reality). BUT WAIT!!! You need to buy 2 membranes instead of one every several years. This puts the payoff even further out.
Honestly... if you want to take the environmental postion, I will understand and even agree with many of the points... but the "cost savings" arguement is never going to get any traction.
As a side note:
You may also want to look into the fact that I live in Pittsburgh PA and pay THE HIGHEST (or second highest last time I looked) PER GALLON COST In the entire COUNTRY! Yes you read the correctly, the most expensive water in the entire country. The funniest part is that our water comes from the Three Rivers and there is no such thing as a water shortage or water storage. The water costs VERY LITTLE to treat and we don't have to re-treat the sewage and produce drinking water. If WE have a water shortage, it means that the Monongahela, Ohio AND Allegheny rivers have dropped at least 10 feet below NAVIGABLE stage. (the water level is controlled by the ARMY CORE OF ENGINEERS). If the rivers drop that low, rest assured that the entire east coast will have LONG been without ANY water and all commerce on the east coast will have long before ground to a halt. You may also find it funny that when other parts of the state are put on a water restriction, we are as well. The honest answer from the numbskulls in Harrisburgh is that [SIC] "It is the fair thing to do!, why should some people of the commonwealth be forced to ration and others not!". When put on the spot, they sidestep the facts and resort to PC spin. Gotta love elected and appointed morons.
Enjoy
BeanAnimal
Premium Member
Hre in Pittsburgh we pay .5735 per 100 gallons of freshwater and the wastewater is billed at .4250 per 100 gallons of freshwater.
So my water costs .9985 per 100 gallons (or $7.47 for the same amount of water that Savatage pays $3.52... in other words more than 100% more per gallon). Of course as mentioned above we also pay meter fees and taxes (which are also much higher than the national average!) The PUC has just asked for another 37% increase btw.
Putting it all together:
MY 3,100 gallons cost me 45.32 with taxes and meter fees. That is a little over $1.46 per 100 gallons. As I we have already established... the fixed fees are really not important to this topic (other than showing how freaking much water costs here due to the wonderful lawmakers in this state.) In addition, my local municipality is asking for a large watewater increase to cover the cost of bringing the towns system up to the new uniform codes (silly for the most part).
This information [PA water rates] is available at www.amwater.com (part of the PAWC webstite).
Bean
So my water costs .9985 per 100 gallons (or $7.47 for the same amount of water that Savatage pays $3.52... in other words more than 100% more per gallon). Of course as mentioned above we also pay meter fees and taxes (which are also much higher than the national average!) The PUC has just asked for another 37% increase btw.
Putting it all together:
MY 3,100 gallons cost me 45.32 with taxes and meter fees. That is a little over $1.46 per 100 gallons. As I we have already established... the fixed fees are really not important to this topic (other than showing how freaking much water costs here due to the wonderful lawmakers in this state.) In addition, my local municipality is asking for a large watewater increase to cover the cost of bringing the towns system up to the new uniform codes (silly for the most part).
This information [PA water rates] is available at www.amwater.com (part of the PAWC webstite).
Bean
BeanAnimal
Premium Member
BTW I have not researched the water rates of every state and town. I got my "most expenisive" information from dozens of online articles that cover the topic of water rates and similar utilites across the country. The subject is rather popular around here because we are [no pun] getting soaked by the morons that run this state.
Bean
Bean
Roland Jacques
Premium Member
Hey Bean, glad you could join us. Ok, be Amazed
like I said earlier I use a lot of water 800 + gallons / mo.
4000 waste (water is $3.30/1000) is only $13.80 mo. Not bad for the winter but in the summer we have a surcharge if you go over 10,000 gallons of usage, it is $4.13 / 1000.
The low waste water from 3 membranes would keep me under the 10,000 gallon threshold. For that 5 month period. instead of 4000 gallons of waste i should have less than 800 gallons
Without waste recovery I use 12,000 Gal a mo at 4.13 = $50.00/mo.
With low waste unit I use 8,800 at $3.30 = $28.60/mo.
savings of $107 just during the 5 summer months. and $74 in the other months.
total waste water cost in 1 year $181 .
As far as pay back less than 1year over a standard RO unit. The 2 extra membranes are only $50/60 each (the rest is just a Roland toy)
The manifold would only have 1 pressure gauge and 1 TDS meters (15 valves, 24 tees, 90s, hose ...) around $150. With this arrangement the accurate would be SPOT ON because I would be using the same gauge and meter for all 14 spots. By opening a valve and bleeding water for each location. I would be actually just be concerned with the differences between all the locations.
To a large part this is an other toy for me, because I really don’t need to know all this info of each spot but that is what I do, play with water.
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Roland Jacques
Premium Member
thanks jdieck, this seems to be a incomplete statement. thier needs to be a flow rate for this to be correct and have any value.
bean you got a formula for this. im a little suprised that i cant find this info.
1/4" RO hose ID is .170". How much flow can go though that small of a hose at the various psi's? (40, 50, 60, 70, 80,) Is their a chart anywhere?
BeanAnimal
Premium Member
Yes in your case the economy of scale makes the project at least worth trying. My "show me" comment was directed to those who use residential water for a typical aquarium 
What about just spending the capital to get a commercial unit with the inline membranes and booster pumps? I would imagine that the througput would be much higher?
What about just spending the capital to get a commercial unit with the inline membranes and booster pumps? I would imagine that the througput would be much higher?
