RO / DI unti

Civicdemon

Civicdemon

Go Big Or Go Home !
Hey guys i just purchased a use RO / DI unit from C list, anyways i pluged it in after Since the guy said it was last used 1 week pryor, and he said the filter where only 2 months old, But anyways i think its creating way to much waste water. i mean it take about 4 hours to make 5 gallons and in that time it fills my Washing machine about 3 times, with water still running down the drain durring the wash cycle. So its making like 12 times the waste water.

What could be some reasons for this ???? It has no presure gage anywhere should i add one ??? if so where ?? also could it be dirty filters ???? should i change them out ?? one more thing i noticed on the spectrapure waster line out it has a insert for reducing the flowrate out of the waste water, mine does not have anything like that just straight tubing, could this be why ???? . Should i add a ball valve and just close it a bit to let less flow out off the waste water ??

Please let me know you guys thanks.

Im planning on mixing my own salwater from now on.
 
Can you post a picture of your full RO/DI setup?
Kits may vary from brand to brand so it is hard to assume what is going on with your system unless we see how the cartridges and tubings are connected.

[You said you feel that it is slow producing RO/DI water]
What is the rated output for your RO/DI unit? Usually it is in terms of gallons per day (GPD) of RO/DI water - it is the RO membrane that dictates this flow.
There is also the waste water ratio which tells you how much waste water will be produced for each volume of RO/DI water.
For example, a ratio of 3:1 would mean that for every unit of RO/DI water produced you would have 3 units of waste water for that same 24 hours.

Based on your example of 5 gallons in 4 hours (1.25 gallons per hour) your current effective GPD is 30. You also estimated the waste ratio to be 12:1.
So if your RO/DI unit is rated at 30GPD and has a waste ratio of 12:1 then it will need 24 hours to make 30 gallons of RO/DI water, and will also kick out 360 gallons of wastewater.
Typically a good mid-market unit would be at 75GPD, with a waste ratio of 3:1 to 4:1 at 55psi going into the RO membrane.

[Pressure gauge]
In my RO/DI kit and a few others that I have seen, the pressure gauge is at the tube going into the RO membrane. This tells you how much water pressure is getting to the RO membrane.
Usually this is the water pressure that really matters because pressure through the RO membrane affects the efficiency of the unit.

[Flow limiter on the waste water exit line]
Putting a flow limiter on the waste water line might end up being counterproductive. You want positive pressure on the IN tube of your RO membrane to maximize the efficiency of the membrane. Putting a flow limiter on the OUT line would counter the pressure through the RO membrane and limit it's efficiency.

[Should you replace the filters?]
I would suggest you shell out a few more dollars and get a brand new membrane, resin, and filter cartridges for your RO/DI unit. That way, you know what equipment parameters you are dealing with and not have to inherit any potential gunk that has been run through that system.
The seller said that the filters are 2 months old. But how much water has gone through the filters and resin in that time frame?
He could have run that unit 24/7 over 2 months for all we know.
 
That is very True. My unit runs from Right to left, first two are connected then it runs up a small hose to the ro membrane, then the RO membrane has two outs one for the waste water and one into the DI filter portion, then from there it goes out to fill your container. SO it has 3 chambers and the Membrane chamber on the top.

I Will get the picture tommorow and post it up.
 
Oh yeah one more question, if i put a spliter with a on off switche where the water come out of the RO membrane into the DI chamber and run a line out of that can i use the water coming out of the Membrane as drinking water ??
 
It shouldn't be producing water that slowly, and it shouldn't be producing that much waste water. It sounds like you need to check your pressure.

If you install a splitter after the RO stages, then you can use the RO water for drinking.
 
This ia the ro membrain in my unit Hydron Tw-1812-75d acording to what i read thatmembrain should be making 75 gpd. You dont think the the wate line needs that little insert thay reduces the water flow out of it? ? Like the spectrapure units?
 
It's hard to tell with the flow limiter without knowing the original intended design of your kit.
Some RO/DI kits have the flow limiter connected on the external tube of the waste water line where you could easily see it. Some have them installed inside the membrane housing.

I did a Google search for that membrane and found the manufacturer's brochure.
It states that it is tested at 75GPD at 60psi.
So I would start with your water pressure first to make sure that you are getting that kind of pressure going into the RO membrane.
http://www.hydronixwater.com/catalog/HDN_brochure.pdf

Once you are sure you are getting the right water pressure and it is still not producing optimal output, then you can look into replacing the membrane and filters and explore adding a flow limiter if it does not have one.
 
Have you guys tride filtech membranes? ?? R they any good? ?? Im going to replace all the filters on the unit. What media do you guy recomend?
 
Im going to change out all the filters tommorow. What filtes would you guys say i should get? ?? I have a 3 chamber unit with the membrane chamber so its a 4 stage i guess.
 
So i got all my stuff from marine depot today. Anyways i swaped out the filters and i noticed on the old filters the guy had left the olastic wroping around the sediment and the carbon filter. Im not sure if you soposto but i took it off the new ones and i turned everything on along with the flow restrictor and everything seems to be flowing way better. Im letring the unit run for a hour and a half before i attempt to collect wat. But anywaysthe why wouldis the guyword lwave the plasticwate wrape on thethe filters.er.
 
Civicdemon said:
Anyways i swaped out the filters and i noticed on the old filters the guy had left the olastic wroping around the sediment and the carbon filter.
Click to expand...

WAIT! Are you talking about the shrink-wrap plastic that is bound tightly around the filters?
If it is what I think it is, then very little water passed through those filters because they still had their packaging wraps on.
Did the old filters even get wet?

If they never got wet (I'm not sure if that's even possible) then those filters are still "brand new" because the water just bypassed them. But if that happened, your RO membrane would have been overloaded with gunk that skipped the sediment filters.
Did you get a new RO membrane as well?

Wow... just... wow.
It reminds me of the time when I was trying to figure out why a printer was not printing and it turned out the packaging seal was still in place. :)
 
Yeah it seems like he just punched in the top and bottom holes and thats it. Nut they where wet. The first sediment filter was lighly brown but only around the top where the hole was. Also noticed my di one is in a hard case. I think its the one that you can refill the media.
 
So i started making water today for my water change on sunday and wow, this thing fills up a 5 gallon in 2 hours, im like yey . i did two 5 gallon jugs right next to eachother, one for the waste and 1 for the good water, and by the side by side looks of things im now only getting 4 times the waste water. Now i have to go get a 32 gallon rubbermaid trash can tomorrow so i can mix my salt water in. I already have a small retunr pump i can use for mixing it and getting it to the DT. im so happy. LOL
 
Good deal.

I hooked up an additional 30 feet of 1/4 tubing on my wastewater line.
While making RO/DI water, I place the waste hose next to a tree or my vegetable bed. If nothing needs watering, I run the line to the pool :)
 

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