I know 15-20K for a full RO system may sound like alot, but you will be done

How much electricity do those whole house units draw at full output?

Whatever your submersible well pump uses just double it because the RO unit has 50% recovery. Add another 1/2 230 volt motor running however long you need it to produce the desired amount of water. I would estimate maximum 8-12 hrs of running time per day for the average family of four. We are not talking excessive amounts of hydro here. Here is a decent unit that typically is used to supply a home http://www.sapphire-group.ca/pdf/Ec...2540-2.pdf

Posted By mnelson61 on 10 Feb 2012 08:23 PM
Whatever your submersible well pump uses just double it because the RO unit has 50% recovery. Add another 1/2 230 volt motor running however long you need it to produce the desired amount of water. I would estimate maximum 8-12 hrs of running time per day for the average family of four. We are not talking excessive amounts of hydro here. Here is a decent unit that typically is used to supply a home http://www.sapphire-group.ca/pdf/Ec...2540-2.pdf

The spec's indicate that this unit produces .83 usg/m @ 25ºc. What does it produce @ 10-12ºc i.e. groundwater temperature? A water saving shower head typically requires 2 gallons per minute.

A whole house RP system will never produce water at a rate to supply the gpm flow demand in the home, for this reason a storage tank and repressurization pump are always sized up. Typically a 300 or 400 gallon tank is good for storage. You are indeed correct that temperature plays an important role in RO membrane performance. There are correction factors for pressure, temperature and TDS. These figures are normally plugged into the graph and a corrected "permeate" flow is calculated. As a rough guess with very high TDS and cold well water I estimate conservatively that the unit will only produce half of its rated output. That's why a 1200 gallon per day system should do fine in a home with only a 300 gallon per day demand. Please understand, these are preliminary estimates and without a water chemistry breakdown I wouldn't suggest anyone go past budgetary pricing. You can see how most people get into trouble undersizing these systems. Although the systems are designed to run continuously,  some off time is necessary to allow the pre-treatment system to regenerate etc etc....

I would estimate maximum 8-12 hrs of running time per day for the average family of four

A well pump runs what, 1-2 hrs a day? So, an RO unit uses 6X - 8X that and then double it? Seems like that might add up to some kilowattage.

The "Sapphire" unit specs don't give any clue to the electrical consumption.

Posted By mnelson61 on 11 Feb 2012 05:43 AM
A whole house RP system will never produce water at a rate to supply the gpm flow demand in the home, for this reason a storage tank and repressurization pump are always sized up. Typically a 300 or 400 gallon tank is good for storage. You are indeed correct that temperature plays an important role in RO membrane performance. There are correction factors for pressure, temperature and TDS. These figures are normally plugged into the graph and a corrected "permeate" flow is calculated. As a rough guess with very high TDS and cold well water I estimate conservatively that the unit will only produce half of its rated output. That's why a 1200 gallon per day system should do fine in a home with only a 300 gallon per day demand. Please understand, these are preliminary estimates and without a water chemistry breakdown I wouldn't suggest anyone go past budgetary pricing. You can see how most people get into trouble undersizing these systems. Although the systems are designed to run continuously,  some off time is necessary to allow the pre-treatment system to regenerate etc etc....

So in op's case there would be around 2 gallons of waste for every gallon of product. If op is on a septic system then needs to add 3 times more capacity. Obviously needs to dispose of this water elsewhere. edited.

A well pump runs what, 1-2 hrs a day? So, an RO unit uses 6X - 8X that and then double it? Seems like that might add up to some kilowattage.

The "Sapphire" unit specs don't give any clue to the electrical consumption.

I'll address this first: Assuming your family used 300 gallons of water in a day. Your well pump would cycle on and off to supply this demand. Let's say your submersible pump has a pumping rate of 5 gpm then the run time would be approximately 1 hour. Now we add an RO system that has a 50% recovery. The family water consumption is still 300 gallons per day but we now need 600 gallons of feedwater to make 300 gallons of permeate water. The result is 600 gal divided by 5 gpm (pump output) now the pump has to run 120 minutes (2 hrs.) So your well pump running time doubled from one hour to two hours. No biggy!
Now we also have the motor to drive the RO pump which in this case is a 230 volt, 3/4 horsepower, so you are probably around 4 amps running load for two hours. Bottom line, hydro is not a big cost factor for these systems.

So in op's case there would be around 7.5 gallons of waste for every gallon of product. If op is on a septic system then needs to add seven times more capacity. Obviously needs to dispose of this water elsewhere. Still 4 x 7.5 x 70 is still 2100 gallons going to waste.

I'm not sure how you got these results so I will try to do a better job explaining the numbers this time: We'll use the same example- 300 gallons per day family usage. RO model ECRO2540-2 with rated output of 1200 GPD. I stated that with high TDS and cold well water that we would get roughly half the rated capacity out of the RO system. What happens is due to the high TDS and temperature, the osmonic pressure is increased significantly. This causes a slower permeate through the membrane, however, due to recycling the concentrate water, we still maintain the 50% recovery. Therefore, our total water used is still 600 gallons. Since the production rate is slower, instead of making 1200 gallons in 24 hours (the rated capacity) we are making 600 in 24 hours. So in this case if we need only 300 gallons we should make that in 12 hours. In my last post I said the RO pump would run two hours, I should have said 12- sorry.

Yeah. After a while, it adds up to real money.

PM me if you want some help

I'm right down the road from you.  My well is salty too, due to the large veins that run all over this area.  I'd like to know what your experiences are. I've never put in a dishwasher because I'm afraid the water will etch all of our glassware.

Can you comment?

minkia38 and oldtechie,

I moved into the area last fall and suffer from the same problem. I've adapted by installing a pump to deliver drinking water from 5 gallon jugs in the basement to the refridgerator and a separate tap at my kitchen sink. I fill the jugs at the grocery. For everything else the well water seems fine. There is some corrosion on the older faucets (home is 12 yrs old) and the previous owners did have a dishwasher which I removed because it was broken. I'm not sure if that was due to sodium content or sitting vacant for a year, or both. I plan to replace with a low-to-medium end dishwasher at some point.

What I have gathered talking with neighbors is that the "cheapest" solution is to have a shallow well drilled. I'm told the only people in the state capable of doing this is Gail Prime Water Well Boring. They recently installed one on an empty lot next door to me after another company failed with deep wells. I have not yet talked with the property owner to get details on the quality. If you're interested in a shallow well you can expect a quote to come in around $100 per foot. 30-40 ft deep seems to be what works in the area. I may go this route at some point.

If you have any more information, please let me know:

Nick
XXX-XXX-XXXX (Phone #'s and email addresses are not allowed in forum posts)

I suggest that R/O is much less expensive and will produce better water than a second well (or any well). Even though I supposedly have "good water", I use R/O for drinking. Better taste and less chemicals.

Purchase a reverse osmosis system. It is not cheap and requires electricity. People usually use this to down-stream of a salt type water softener to remove all of the sodium that it ionizes out so you can drink the water and not raise your blood sodium level. It removes everything else too. cheers

My RO system uses a "permeate pump" that runs off water pressure (vs electricity). This increases output, efficiency and water quality (as compared to no pump).

If my next door neighbor had a well with good water, I'd talk to him about sharing it.