Water Filtration Expert Needed

scbauer

The Buff Reefer
Premium Member
Hi Everyone, I have a small dilemma. I just bought a new RO/DI unit and I already know exactly where I will install it. There is a feed hose going into my refrigerator and my garage (and location of my new tank) is just on the other side, so I can easily drill a small hole through the wall to feed the RO/DI unit. My problem is, I don't know where to connect the "waste water" line.

I'm thinking I have 3 options:

1) Run a long line around the garage and just let the waste water drain out the front of the garage, down the driveway and into the street/sewer.

2) Buy a large garbage can and let the waste water drain into that, then dump the can ever few weeks when it gets full.

3) There just happens to be a water softener (Kenmore UltraSoft 275) sitting right next to where I will install the RO/DI unit. I know that the water softener has a "drain" line to drain the brine water after a cleaning cycle. My question here is, are water softener drain lines pressurized? I believe my drain line runs up through the wall, over a few doors, into the laundry room, then drains into the laundry room drain. I'm 90% sure of that, but not 100%. Basically, there is a small (maybe 3/8" diameter) copper pipe that comes out of the wall between the input and output lines for the water softener. There is a small green tube connected between the water softener drain line and this copper pipe. Do you think I would be able to tap into that drain line and have my RO/DI unit use that drain, too?

Number 3 would certainly be the best option, but I'm worried that the water softener might drain into the "waste output" of the RO/DI unit. I really don't know how these things work, but common sense would tell me that since both units (softener and RO) are hooked up to the same plumbing, the water pressure should be the same on both, and therefore 1 could not force waste water into the other, but I really don't know if this is true.

I guess another option could be to simply drain into the main salt tank of the water softener, but again, I don't know how the softener works and this might completely screw up the softener. I believe a specific amount of water is measured into the salt tank in order to make the brine, so if I just start filling that tank with RO waste water, there might be too much water in the tank when the softener needs to make brine and clean the resin.

HELP HELP HELP!!!

Thanks everyone!

-Scott
 

rbursek

In Memoriam
The waste water line from the softner would have to be preasurized to get it over the hight of the door. Your waste on the RODI depending on the unit could give you 4gal for every gal of RO/DI, so a bucket for the waste would have to be monitored so it does not over flow.
 

rbursek

In Memoriam
You are right about the amount of water going into the brine tank,
it would not be the place to drain to.
 

scbauer

The Buff Reefer
Premium Member
<a href=showthread.php?s=&postid=12197577#post12197577 target=_blank>Originally posted</a> by rbursek
You are right about the amount of water going into the brine tank,
it would not be the place to drain to.
That's what I thought. Thanks for confirming that.

-Scott
 

scbauer

The Buff Reefer
Premium Member
<a href=showthread.php?s=&postid=12197543#post12197543 target=_blank>Originally posted</a> by rbursek
The waste water line from the softner would have to be preasurized to get it over the hight of the door. Your waste on the RODI depending on the unit could give you 4gal for every gal of RO/DI, so a bucket for the waste would have to be monitored so it does not over flow.

One note, I don't plan on hooking my RO unit directly to a float switch, I'm just too paranoid that it will get stuck on. Instead I will have about a 10 gallon resivoir that I will manually fill and this will be connected to my top-off. This way, I will only be draining "waste" water while I'm around to watch it.

If I went the bucket route, it would probably be a 50-gallon garbage can or something like that, so I should be okay, but this isn't the preferred method.

My big question, then, in response to your post, is how would the softener's waste water drain be pressurized? Does it simply use the water pressure from the main water line, or is there a separate pump? If it is the water pressure from the main line, am I correct in thinking that the pressure in the softener will be equal to the pressure in the RO unit and therefore water will not flow backwards down either of the drain lines?

Would an auto-shutoff valve on my RO unit help at all? One more variable, my RO unit will be used for drinking water, too, so I will have a 3-gallon pressurized storage tank connected to the RO system. Not sure if this is an issue as I think the water would have to go through the RO membrane (backwards) to get from the softener to the RO storage tank.

Thanks for the quick response, rbursek.

-Scott
 

rbursek

In Memoriam
I belive from my softners the waste is just water preasure no pump. If you can get a check valve for your waste Ro water that would prevent any of the softner waste from back flowing into the RO.
 

rbursek

In Memoriam
Another thought, most softners are set to regenerate at night, so you could put a manual valve on the RO waste line and only open it when making water and make sure you are making water when the softner is no going to regenerate.
 

scbauer

The Buff Reefer
Premium Member
I like it! I think this crazy "diet" thing that I'm on is messing up my mind. I don't know why I didn't think of a check valve.

Actually, I guess I am able to think... I just realized that I will be making RO water at irregular intervals because this unit will also be hooked up to our refrigerator. But, as you said, a check valve should take care of this.

Anybody know where I can get a check valve for 1/4" JG fittings?

Thanks again, Bob!

-Scott
 

scbauer

The Buff Reefer
Premium Member
I just found them on JohnGuest.com, but not sure who sells them retail. Savko didn't have them, I'll check MarineDepot.
 

DarG

New member
Couple other simple options.

Where is you AC air handler? If you can get to that there is a drain going outside somewhere.

Also, since you are near a garage wall, you could always just run a piece of PVC or other pipe or tubing at a slight slope and directly through an outside wall. You would only have to drill a small hole through the wall.

My RO/DI is set up in the garage on an outside concrete wall. I drilled through the wall then expanded the hole large enough to bring in two pieces of 1/2" PVC pipe. One has a hose valve on it and is tapped into the outside water line for the water hose. The other just goes out and down the wall as a drain for the waste. Gaps were filled in with a concrete and mortar patch like spackling paste meant for concrete.

The point is that if you have a concrete wall, popping a drain line through it is not a big deal.
 

scbauer

The Buff Reefer
Premium Member
Hey DarG, thanks for the info. My AC unit is in the attic on the opposite side of the house, above the second floor, so that isn't feasible.

I was considering simply draining to the side of the house, but I would rather not do that since it would be in the front yard and the side of the garage is essentially common area for me and our neighbor. Don't want to **** off the homeowners association. :)

Thanks for the ideas, though. I still feel the best be it to tap into a sewer line somehow, and the only one close is the waste line for the water softener. I think using a JG check valve then tapping into the waste of the softener should work just fine.

-Scott
 

gkyle

Premium Member
The simplest thing to do is install the RO/DO under your sink, use a simple tap on the cold water line to feed it, and plumb the waste output into the same drain being used by the sink. The water tubing itself is very easy to route anywhere you need to since it requires such a small hole. That's what I did and then I drilled a small hole under the sink through to the open basement. Then all my lines run from there.

Might not work for you, but the hassle of those buckets will add up over time... Also, I started out without float valves at first thinking I'd be there anyway. After destroying a hardwood floor, I changed my mind and spent the $20.
 

AZDesertRat

In Memoriam
Normally a water softener brine waste line is a gravity line just like a sink? Are you sure it does not go down under the floor and across to where it dumps into the sanitary sewer?
Do you have a laundry sink or washing machine close? Mine are both in my garage so mounting the RO/DI right above the sink was the obvious choice for me. You also want to feed the RO/DI unit with softened water here in the southwest, it will help the RO membrane as it does much of the work for it.

Mounting the unit near or under as ink might be the better choice since you will have access to both cold water and a drain, then run a single 1/4" RO/DI treated water line to where ever you want it from that point.
 

DarG

New member
All you need, if you dont trust an electrical float valve / shut off system, is a cheap manual float valve that simply stops the flow of the product water when the float rises. I used one of these for years and never had them fail. It would be tough for one to fail, there is no hard water or algae or particulate build up that can cause to seal to degrade or not fully close the flow. The waste water continues to flow however until the supply is shut off.

Now I use an electrical solenoid to shut off flow controlled by a float valve as well as the passive float as a back up.
 

scbauer

The Buff Reefer
Premium Member
<a href=showthread.php?s=&postid=12198687#post12198687 target=_blank>Originally posted</a> by AZDesertRat
Normally a water softener brine waste line is a gravity line just like a sink? Are you sure it does not go down under the floor and across to where it dumps into the sanitary sewer?
Do you have a laundry sink or washing machine close? Mine are both in my garage so mounting the RO/DI right above the sink was the obvious choice for me. You also want to feed the RO/DI unit with softened water here in the southwest, it will help the RO membrane as it does much of the work for it.

Mounting the unit near or under as ink might be the better choice since you will have access to both cold water and a drain, then run a single 1/4" RO/DI treated water line to where ever you want it from that point.

Thanks for the input. I am not sure if the waste line goes up or down, but the point where it drains into the "washing machine sewer drain" is above the point where it connects to the softener.

As for plumbing under the sink, it just isn't going to happen. At first I thought I could do it since I already have a line running from under the sink to the back of the refrigerator and thought I could just use that, but then I realized I need 2 lines, one for RO to the refrigerator and one for RO/DI to the tank. I'm not going to pull another tube, especially since it either goes through the studs (and might go through holes that are only big enough for a single tube) or through the concrete slab foundation.

I've decided I'll try to plumb the RO waste line into the softener waste line using a check valve. Does anybody think there is an issue with the RO waste line having some pressure or will the check valve completely take care of that issue?

I have read many times that it is good to feed the RO unit with soft water. I guess it's easier for the RO/DI unit to remove any sodium that the softener adds as opposed to the heavy metals that the softener removes.

-Scott
 

scbauer

The Buff Reefer
Premium Member
<a href=showthread.php?s=&postid=12198749#post12198749 target=_blank>Originally posted</a> by DarG
All you need, if you dont trust an electrical float valve / shut off system, is a cheap manual float valve that simply stops the flow of the product water when the float rises. I used one of these for years and never had them fail. It would be tough for one to fail, there is no hard water or algae or particulate build up that can cause to seal to degrade or not fully close the flow. The waste water continues to flow however until the supply is shut off.

Now I use an electrical solenoid to shut off flow controlled by a float valve as well as the passive float as a back up.
DarG, I'm not worried about the top-off system. I built my own ATO using electronic float switches and it works GREAT! I'm just slightly paranoid about allowing my ATO to connect to a constant flow of water. All it takes is 1 time and you can lose a whole tank. It isn't worth it to me. If I'm going to be gone for a few days, I'll just use a slightly larger resivoir. I was really just looking for input on the installation of the RO unit. When the tank planning starts I'll reevaluate my ATO system.

-Scott
 

AZDesertRat

In Memoriam
Wasting against a check valve or pressurized system of any sort will affect the waste ratio. It will also be a plumbing code violation since you have a direct connection with a presurized or other sanitary sewer line without an air gap. RO membranes are designed to be flushed to atmosphere. When hooked to a sewer drain they require an air gap faucet to meet plumbing code and with the air gap you cannot have any backpressure or it will leak.

Its going to be tough figuring out how much effect the backpressure will have on the waste ratio since it is going into a sealed pipe where you cannot either measure the backpressure or visibly see and measure the flow rate to compare to the product or good water output.
 

scbauer

The Buff Reefer
Premium Member
As they say, a picture is worth 1,000,000,000,000 words, right? Or something like that. Hope this helps. There will be NO code violations :)

46146RO_Waste_Line.JPG
 

scbauer

The Buff Reefer
Premium Member
As you can see, there is some water pressure pushing back on the waste line (even when the softener and RO units are off) because of the head pressure of the pipe going up into the wall.

Hope the picture helps.

-Scott
 
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