Making RO Water

[Vamsi]

Please help me decipher this. I have made about 50 gallons of RO water yesterday. I did take a picture of my water meter before and after. Attached are the pictures A for before and B for after. So did I technically burn 500 gallons to make 50 gallons ? Is my math correct. If that is correct, then my ratio for waster waster to good water is way off right ?

Have a booster pump feeding the RO and I get about 80 PSI. I can double check that.

More context - Single guy, no kids and all. I did take a 5-7 mins shower and to be on the high side, assume I used 50 gallons of water. Still my ratios are way off.

 

[vetteguy53081]

According to meter, you used 40 gallons.

Example:
This meter says that 5,628,340 gallons have been used in total since the installation date.

 

[chiefifd]

Typically you will use between 3 to 5 gallons of water for every one gallon of RO water produced. It all depends on water pressure, water temperature and your filters condition. I know you can run multiple RO membranes in series to cut down on waste water.

 

[Chibils]

According to meter, you used 40 gallons.

Example:
This meter says that 5,628,340 gallons have been used in total since the installation date.

What's confusing me (and OP, I assume) is that his water meter has two stationary zeros at the end. It makes it look like the first digit is hundreds.

 

[chipmunkofdoom2]

It's unlikely that your RO unit used this much water. The Filmtec membranes we use are designed to have a brine to permeate (waste to product) ratio of 4 : 1, but most hobby RO units starve the membrane of brine to "reduce waste water." Your ratio is probably closer to 2:1. If your RO unit truly does have a 10 : 1 ratio, there's a giant hole in the membrane that's leaking water.

The most likely culprit is your average household tap water use. The average family in the US uses 300 gallons of water per day. If your RO unit has a 2:1 ratio, which it probably does, that means your RO unit used a total of about 150 gallons to make 50 gallons of purified water. If your family used another 300 gallons, that's about 450 gallons. Your meter shows an increase of about 500 gallons. So, the numbers add up.

 

[vetteguy53081]

What's confusing me (and OP, I assume) is that his water meter has two stationary zeros at the end. It makes it look like the first digit is hundreds.

Most utilities have a stationery zero.
If this meter was used to monitorRO only and no other home use. . . . it is accurate. IF it is in hundreds, it is possible, 2 or more showers or baths and even laundry would place it in hundreds. IF it is RO only, I would have the utility company check meter for accuracy

 

[Vamsi]

Hi,
It's not just RO, meter for the entire household. There is another meter in my basement, closer to where the pressure for the house can be adjusted. The next time I make water, I will check on that. I have a spectra pure RO unit, 180 GPD capacity. I believe it is a 2:1 ratio. What is the recommended temp of the water to get optimal performance?

Thanks.

 

[Vamsi]

Ok, I see 77F is the recommendation for optimal production.

 

[Water Dog]

Grab 2 measuring cups. Put the product water line in one cup and the waste water line in the other. You can now measure a given amount of product water and the amount to wastewater it takes to produce it. Then verify with your meters.

 

[Vamsi]

Grab 2 measuring cups. Put the product water line in one cup and the waste water line in the other. You can now measure a given amount of product water and the amount to wastewater it takes to produce it. Then verify with your meters.

Thank you, I will try this.