# Question about RO systems



## Gilda (Jul 18, 2009)

I have aquired a RO system and know nothing about them. Reading on the web , it says if it makes 4 gals a day you could have up to 40 gals of waste water. Do you guys see an increase in your water(utility )bill if 40 gals goes down the drain so to speak ? Scary thought to think that much water is wasted. Am I confused on what I am reading ? (It wouldn't be the first time !)

Any hints advice on using /installing is much appreciated !!
TIA !


----------



## SlipperFan (Jul 18, 2009)

No, but I'm thinking of getting one, so any thoughts would be appreciated here, also!


----------



## Ernie (Jul 18, 2009)

Yes, RO units are wasteful. Our ratio is about 1 gallon made to 4 gallons brine. 

-Ernie


----------



## Wendy (Jul 18, 2009)

Also interested in the answer as I am about to order one.

For anyone interested, Ray Barkalow of First Rays Orchids, offers a bare bone system on his web site. Much less costly than other systems and you get exactly what you need and no more. I will be ordering from Ray.


----------



## Rick (Jul 18, 2009)

Gilda said:


> Any hints advice on using /installing is much appreciated !!
> TIA !



If you are on a chlorinated city water, I would put a small activated carbon and a ultra fine particulate filter ahead of it to save your membranes. 

I believe the RO membranes are "allergic" to chlorine so I've seen both carbon and thiosulfate injection systems used for pretreating of city water.


----------



## Ernie (Jul 18, 2009)

There are two types of membranes- chlorine "allergic" (TFC= thin film composite) and chlorine tolerant (CTA= Chicago Transit Authority, wait, I mean cellulose triacetate). Many household RO systems have a carbon filter to remove chlorine etc. Those using a TFC membrane put the carbon before the membrane, those with CTA put the carbon after. 

We use a 5 stage system, 100 gpd (gallons per day) with a TFC membrane. The unit has a fibrous prefilter to get the big stuff, a carbon prefilter, the TFC membrane, a carbon post filter, and a final metallic filter ring to prevent bacteria from growing from the faucet backwards into the filtering bits. The water is stored in a pressurized tank for delivery on demand. 

-Ernie


----------



## Candace (Jul 18, 2009)

Gilda, yes there is quite a lot of waste. I've felt rather guilty about it over the years so last year I rigged something up where the waste water is diverted into my evap. cooler. The pads get a bit cruddier with all the minerals but it saves quite a bit of water, I think. You don't want to use the brine on landscape plants. But, if you've got an evap. cooler you could go that route.


----------



## Rick (Jul 18, 2009)

Ernie said:


> Yes, RO units are wasteful. Our ratio is about 1 gallon made to 4 gallons brine.
> 
> -Ernie



Basic household units that only run on household water pressure are wasteful.

There are systems that run at boosted pressures with nested or sequential membranes to reduce waste. But that means both increased capital and operating $$$

The efficiency of the system is related to contact time and pressure. To maximize the efficiency of the system you have, run it at the slowest flow rate and the highest pressures you can live with. You may not have much option on the pressure but many household systems can go up to 100 psi (your house hold plumbing probably won't like that though). But if you only need a couple gallons per day, then take the entire 24 hours to dribble the water into the storage tank.


----------



## Rick (Jul 18, 2009)

Candace said:


> Gilda, yes there is quite a lot of waste. I've felt rather guilty about it over the years so last year I rigged something up where the waste water is diverted into my evap. cooler. The pads get a bit cruddier with all the minerals but it saves quite a bit of water, I think. You don't want to use the brine on landscape plants. But, if you've got an evap. cooler you could go that route.



Apparently GE has a system that pumps the waste stream back into your household hot water side for re use in the shower/bath and laundry. Some people also put a water softening or mixed bed system ahead of the RO so the reject will have less Ca/Mg and more Na

There can be allot of specific cases for salt treatment alternatives.


----------



## McPaph (Jul 18, 2009)

it should be a 4to1 ratio 4 gallons waste for 1 gallon good water. I like Candace's method with the evap. cooler. If you only have a few plants and your going to put it under your sink you would have to be real creative to use the waste water for anything with out hoses everywhere across your kitchen or Major construction. if you can live with the waste the 5 stage works pretty good. with a 3 gallon pressurized storage tank. It has 1 sediment filter and 2 carbon pre filters before the membrane and a carbon post filter. definitely get one that comes with all the filters and membrane because that's most of the cost. if only a few plants the 18 gallon per day membrane works. I like my 50 GPD membrane. they all fit in the same housing. you just have to change the flow restrictor on the waist water. Just be prepared to change out the pre filters and some cleaning in the storage tank. you need some sort of storage tank because the water just trickles out. They also make a no waste system that's more expensive but i don't know how that works. 

Mick


----------



## McPaph (Jul 18, 2009)

If you acquired a used one its best to Check the tank pressure, it should be about 8 lbs. you will have to run some bleach or something like that to flush out the tank. then change out the pre filters and then you will need a ppm meter to check your water to see if your membrane is any good. In that order. My water comes out at 12ppm and a little higher wouldn't hurt anything. The tank can grow Biological (bioslime, mold, or fungi).
you can look up almost any brand and they have online manuals to help install. you could even make it portable, cabinet and wheels and hook it to a water hose. the membrane just cant dry out it will go bad.
Mick


----------



## NYEric (Jul 18, 2009)

Yes it's wastefull, but my water is included in my maintenance bill. I also have the expense of buying filters about every 6 months but the muddy crud removed from my "drinking water" makes it worthwhile.


----------



## Gilda (Jul 18, 2009)

Thanks to all for their input. I think you helped me as well as others.

We found a Micromax 6000 TFC brand new in a box that had never been opened at a thrift store for $6.00 !!!!!!!!!

Looking for info on the web about the make/model I found one that was listed on the Kansas City Craig's List. 
Here is the link :
http://kansascity.craigslist.org/hsh/1231394945.html

I think we hit the jackpot ! Your opnions ??


----------



## Ray (Jul 19, 2009)

A good system typically has - in order of flow - a sediment filter to remove suspended solids, one or two carbon filters for capturing mostly organic compounds (that's the difference between a 4-, and 5-stage unit), the RO membrane itself, then an additional carbon "polishing" filter. (I'm not convinced of the benefit of a 5-stage unit, and in the three years I've been selling systems and RO components, have never sold a single 5-stager.)

As to the waste water - I prefer to call it "flush" water (doesn't sound so wasteful) - something in the range of 4:1 or 5:1 is "standard". However, there are definite ways to improve upon that.

As Rick pointed out, there are pumps available (about $200) to push that flush water back into your hot water supply, so it gets used. (It goes into the hot water after your heater, so the extra minerals don't precipitate.)

Another alternative - about 1/3rd the cost and one I recommend to anyone - is a so-called "permeate pump". Added onto any RO system (up to about a 100 gpd rated capacity), it uses the flush water to pressurize the membrane, producing water at a faster rate and greatly reducing the amount of flush water generated.

I added one to the BBRO ("Bare-Bones") system I use for refilling fish tanks, and it cut the refill time to somewhere between a half and a third of it's former performance, and the flush to the sink is a slow stream rather than its former "jet" of water. I recently received an email from a customer in Arizona who added one to a 60 gpd system, telling me that the flush stream volume is less than 20% of what it was. (Neither of those is very scientific, and are probably nothing more than "eye-ball estimates", but the improvement is significant!)


----------



## Toddster63 (Jul 19, 2009)

You can also add a second RO membrane to your system, that the flush (waste) water from the first RO membrane goes through. This particularly works well if you have high pressure with your city water (like I do), or if you have a booster pump attached to your RO system. With the twin RO membranes I get MUCH less waste and the water production is twice as fast (and twice as much too...! ) My ten gallon RO tank fills up in about 90 minutes.

One of my favorite reef aquarium suppliers makes a "kit" to easily install this second membrane (which is what I used). Plus they have a video showing how easy installation is. You can find out more HERE.


----------



## Toddster63 (Jul 19, 2009)

Gilda said:


> Thanks to all for their input. I think you helped me as well as others.
> 
> We found a Micromax 6000 TFC brand new in a box that had never been opened at a thrift store for $6.00 !!!!!!!!!
> 
> ...



Gilda, for $200, that's a decent buy. But if you shop around the net, you can find a system, complete with the 3 gallon bladder storage tank, for as little as $120 (though they often up the shipping costs!) However, if you are new to RO systems (and less than plumbing savy), I really recommend getting your system from someone with good strong customer service that can help you out if you get confused about what goes where. Ray sells a real nice system, and when you factor in his free shipping, his price ($189) is very reasonable indeed (plus you're supporting the orchid community which is always nice).


----------



## Rick (Jul 19, 2009)

Both Ray and Toddster63 are referring to the "nested and sequential" membrane systems that I mentioned generally in my earlier post.

Ray do you have a specific kit for the recycle "permeate pump" that you mentioned in your post?

Presently I'm spoiled with having RO water available to me at work, and I only bring home 5-10 gallons a week (so I haven't even taken the unit I purchased for my home use out of the box). Our work system also has internal booster pumps w/ recycle with little waste. But eventually I'm going to have to get the home unit out of the box.


----------



## Candace (Jul 19, 2009)

Gilda, you scored!


----------



## Gilda (Jul 19, 2009)

Toddster63 said:


> Gilda, for $200, that's a decent buy. ).



I think you misunderstood my post... we were't buying the one on Craig's list...we bought a brand new one just like that one for *$6.00 *!


----------



## NYEric (Jul 19, 2009)

Yes! Can you now find me some EYOF dallesandroi hybrids?!


----------



## Rick (Jul 19, 2009)

Gilda said:


> I think you misunderstood my post... we were't buying the one on Craig's list...we bought a brand new one just like that one for *$6.00 *!



That is awesome Gilda! You're on well water aren't you? Maybe you can add a permeate pump that Ray mentioned.


----------



## Toddster63 (Jul 19, 2009)

Gilda said:


> I think you misunderstood my post... we were't buying the one on Craig's list...we bought a brand new one just like that one for *$6.00 *!


Oh, WOW, I sure did...! That's great, $6.00! Awesome buy!


----------



## Gilda (Jul 20, 2009)

NYEric said:


> Yes! Can you now find me some EYOF dallesandroi hybrids?!



Eric, your posts always make me smile !

Rick, no we are on city water. Does that make a difference ?


----------



## Ray (Jul 20, 2009)

Rick said:


> Both Ray and Toddster63 are referring to the "nested and sequential" membrane systems that I mentioned generally in my earlier post.
> 
> Ray do you have a specific kit for the recycle "permeate pump" that you mentioned in your post?
> 
> Presently I'm spoiled with having RO water available to me at work, and I only bring home 5-10 gallons a week (so I haven't even taken the unit I purchased for my home use out of the box). Our work system also has internal booster pumps w/ recycle with little waste. But eventually I'm going to have to get the home unit out of the box.



Rick, what I carry is a pump with mounting bracket, plus some extra tubing and an installation diagram (that is also online).

The pump has 4 quick-connects, so it's really just a matter of disconnecting two tubes on the RO system, inserting them into the pump, with the extra tubing used in reconnecting.


----------



## luvsorchids (Jul 20, 2009)

It sounds like everyone here is all set and ready to go :

http://www.good.is/post/pee-totaler/?gt1=48001

Susan


----------



## Alec (Jul 20, 2009)

One item that may be worth thinking carefully about, depending on your setup, is a water cut-off device in case you forget to cut it off and your container overflows. 
I've managed a couple of small floods over the years, but the cut off device takes maybe 98% of the risk out of it.

Alec


----------



## Wendy (Jul 20, 2009)

Now I'm wondering how all the waste water would affect our water bill since we pay for what we use. I don't want to get a huge bill for all that waste water going down the drain and only being able to use 1/4 of it.


----------



## gonewild (Jul 20, 2009)

Wendy said:


> Now I'm wondering how all the waste water would affect our water bill since we pay for what we use. I don't want to get a huge bill for all that waste water going down the drain and only being able to use 1/4 of it.



Look at your water bill and determine how much you pay per cubic foot of water, above any set minimum charges. Divide that amount by 7.5 and that is how much you will be paying per gallon of waste water.


----------



## Rick (Jul 20, 2009)

I think the matter of waste should include considerations of conservation as well as cost, although cost will be the first thing that will irk you.


----------



## NYEric (Jul 20, 2009)

Get the permeate pump addt'l.


----------



## Ray (Jul 21, 2009)

Alec said:


> One item that may be worth thinking carefully about, depending on your setup, is a water cut-off device in case you forget to cut it off and your container overflows.
> I've managed a couple of small floods over the years, but the cut off device takes maybe 98% of the risk out of it.
> 
> Alec


Right on, Alec.

Most systems I have seen (and the ones I sell) have a (typically) 3-gallon bladder tank and faucet as the built-in storage- and delivery means, and all have a pressure cutoff switch. If the faucet is closed, the unit produces pure- and flush water until the pressure in the tank comes up to a certain level, and then the system back-pressure trips the switch, cutting off all flow to the membrane. It is both a conservation and membrane-preservation mechanism.

In my greenhouse, on the other hand, I have employed neither the faucet nor bladder tank, and the pure water goes into a large volume storage tank containing a float valve. Again, when the float valve closes, the back-pressure trips the switch, and all flow stops.


----------



## montanum (Jul 25, 2009)

I was thinking about getting a GE Merlin (about $350) next year which can provide up to 720gal of RO water per day for the greenhouse, pond, bog and orchids (oh, and probably for humans too, I guess). This was recommended to me be the guys at Sarracenia NW who use copious amounts of RO water for their carnivorous plants. They liked it because it can be turned on and used as a normal hose without waiting for the tank to fill. The manual says that about 1gal of RO to 3 gal waste water.

Anyone tried one?

Ross


----------

