Zero Waste RO

[sphelps]

This appears to be a very simple concept to save wasted water from your RO unit. I recall looking at this before but only recently did I become interested as a result from another thread.

So they do sell retrofit kits but I figure one could easily find parts locally and make this a simple DIY project and perhaps even improve on it. So lets discuss.

Links:
https://www.wattspremier.com/product...e-Retrofit-Kit

https://www.freshwatersystems.com/p-...id=10050&qid=0

http://www.costco.com/Browse/Product...=1&topnav=&s=1

[banditpowdercoat]

OK, with that first link, having an electric pump on there, Now I can see how it will work.

When the RO water is used, the pressure in the pressure sw drops, causeing the elec pump to turn on. Because the waste and inlet water are taken from the house supplys, they are both at same pressure.
The pump then increases the membrane inlet pressure higher than the waste presure. Waste is forced back through the hot water line.

BUT, because the Hot Water is acctually plumbed from the same source as the cold, the waste acctually flows backwards through the Hot water line, back towards the Hot Water Tank, and eventually out the tank's inlet, to the cold line.

I can see this system is best for a small RO system. If your like me, and make 30g+ of RO at once. Well, at a 4:1 ratio, thats 120g of waste, best case, you and I know it's more like 200g waste. Most HW tanks are what 40g? So, you would in essence be draining your hot water tank 5 times, and recirculating through your RO system.

Now, making a gallon of water here, cup there, I can see that being a great solution

[Binare]

Like Dan mentioned, this system seems great for small tanks, filling a pot or grabbin a glass of water, but for any scale beyond that... Your wasting electricity or gas to heat up hot water tank fulls of water needlessly, last time I checked gas and electricity costs more then water.

[sphelps]

OK lets think about this for a minute, do most people actually use 30 gallons a day? Yes many will make up 30 gallons or more on occasion for water changes but we don't have to. It wouldn't much harder to fill a storage container over a few days rather than all at once. Also the introduction of a booster pump makes it possible to lower the ratio of waste water. So if one could adjust their water usage to about 10 gallons a day you might only be looking at around 20-30 gallons of waste.

Personally I'd be good with a gallon a day for water changes (~7 gal/week wc) and around 5 gallons a day for top off (overkill, probably less) so I'd say 10 gal/day is above average but a a good safe number.

The other question I have is what happens at the water heater? Will water be pushed back into the cold supply or will it drain out? I'm no expert on this.

Remember the idea is also to improve on whats available so just because what is already out there doesn't really work for you doesn't mean the idea is dead or hopeless. There are other purposes to DIY than saving money.

Any ideas?

[mark]

from the non green side.

A gallon of water is worth a penny.

Technically it's 6/10 of a cents but in Edmonton you also pay for each gallon you put in the drain so combined, a penny a gallon.

[RuGlu6]

Originally Posted by mark

from the non green side.

A gallon of water is worth a penny.

Technically it's 6/10 of a cents but in Edmonton you also pay for each gallon you put in the drain so combined, a penny a gallon.

+1

Also from a green...er point of view,
Dilution of the toxic sewer water with RO/DI so called "waste".

The more non toxic cleaner water goes in to the sewer the less toxic the sewer water becomes to the environment.

We all know what people are flushing down the toilet right? Not so green...and environmentally friendly.

Now how about medical labs, unsold drugs, pills, washing detergents, soap.
Also think about industrial waste that is being leached, solvents, paint.
Pig/chicken etc. farming, pesticides, herbicides, insecticides...

Perhaps its ok to dilute some of that wit so called "waste" water from RO/DI.

Maybe we should ask ourselves a question: why they have a campaign to "save water" and "save Electricity"? is it because they want to save our planet or because they want to sell it down south and make a $?

Asking a question "who will benefit?", "who makes $"?
Following the money usually helps getting a bigger picture...
JMO.

[banditpowdercoat]

My thoughts exactly, RuGlu6. Especially on electricity in BC. Our power is primarily form HydroElectric dam's. Pretty green, renewable resourse if you ask me. Then why the Power Smart campaign? It does not harm our enviroment to generate electricity from water. Ohh wait, California is willing to pay 3-5x more than we pay for our power, lets conserve power, and sell to US. Then what does Cali do?? doesn't pay. But were still sending down power.




Mark, do you have meters on your homes sewer lines too in Edm?

[mark]

California is not paying it's bill? going to google that

In Edmonton there's only a water meter, but you also pay a drainage fee that's based on the amount of water coming into the house and lot size.

[banditpowdercoat]

I remember after we started sending power to Cali, they had bill, somewhere in Millions, But old Arnie said they couldn't pay. I can't remember all teh details, But I do remember Hydro being "nice" and waiving the debt. It was a while ago I remember that

[sphelps]

OK well the idea here is reuse your waste water from your RO units. To say that it's better to waste the water since it has potential to help out sewage issues is somewhat ridiculous in my mind. If this were the case, then for the same reasons we shouldn't bother to fix leaking faucets and running toilets. The average household wastes more than enough water to help with those issues already, and if a problem did exist with water treatment I don't think the solution would involve wasting more water.

Saving water is a good idea, and really this is something everyone should be interested in regardless if water is cheap or not. From a green point of view it's as simple as reducing your consumption, that's it. It doesn't involve politics and I see little relevance between the two. Yes power companies promote energy saving for other reasons than to save you money but so what? That doesn't mean you should leave the lights on 24/7, it's a simple system that both parties benefit from, you save money and the power company makes more money. Is it perfect? Absolutely not but it doesn't mean we should be wasteful.