ro/di waste water problem insanely to much

[Reeling Reefer]

I have a brand new ro/di 4 stage klean water 100gpd system and its producing an insane amount of waste water. the good water is 80 gallons a day coming out at 0 tds seems fine but the waste water is flowing way to fast wasting a gallon a minute . my pressure is low 30 psi but what could be causing this? I was told get a booster pump an additional membrane to help this? is the restrictor not working on the waste side? why is it coming out so fast? is the good water which is 0 tds good to use ? the tap water tests at 25 tds 

[wildcrazyjoker81]

RODI units as a whole waste a ton of water sadly. You seem to already know your issues of needing a booster pump and even adding a second membrane. I have both and it has drastically reduced my waste water. I know many here actually reuse their waste water so maybe that is an option to feel like less water has been wasted.

[davidm]

I'm filling up my laundry machine with waste water while making Ro/DI as we "speak". 

[FishingandReefing]

If I remember correctly, it takes 5 gallon of water to make 1 gallon of rodi. I usually make 40-50g rodi per week, that’s about 250g of tap water. However, at about $.005 per gallon, that’s about $1.25. Of course, the more gallons you used, the service fees go up but somehow I feel that spending extra money on another membrane and boosters bump might not truly save you money? I don’t know. I almost pull the trigger on a booster during cyber money sale.

I have a aquaticlife 100GPD 4 stage.

Sediment and carbon both for $15 (6months)

Membrane $50 (1 year)

DI $25 (3-5 months)


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[Reeling Reefer]

I am at like a 20 to 1 ratio

[therootcause]

I have a brand new ro/di 4 stage klean water 100gpd system and its producing an insane amount of waste water. the good water is 80 gallons a day coming out at 0 tds seems fine but the waste water is flowing way to fast wasting a gallon a minute . my pressure is low 30 psi but what could be causing this? I was told get a booster pump an additional membrane to help this? is the restrictor not working on the waste side? why is it coming out so fast? is the good water which is 0 tds good to use ? the tap water tests at 25 tds 

I’m not familiar with this system, but could it be hooked up incorrectly?


My water in Glen Burnie is 400TDS I think. I can tell you that if my water was 25 TDS I wouldn’t even be using an RODI.

** this is my unpopular opinion only **


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[FishingandReefing]

I am at like a 20 to 1 ratio

You mean yours take 20g to make 1g of rodi? How do you know? I just estimated mind based on the flow rate or maybe next time will try to fill the waste water with a bucket and see. But usually is 5 to 1.


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[FishingandReefing]

I’m not familiar with this system, but could it be hooked up incorrectly?


My water in Glen Burnie is 400TDS I think. I can tell you that if my water was 25 TDS I wouldn’t even be using an RODI.

** this is my unpopular opinion only **


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Kind of same here in moco. Without DI I am prob at around 40.


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[AlanM]

is it possible that you have a flush valve on your RO membrane that is set in the wrong position?  If it's wrong, then it isn't allowing the flow restrictor to operate and is rinsing water past the waste side of the membrane without letting pressure build up and make good water.  Normal ratios of waste to RO are around 4:1 or 5:1.  Much more than that and your membrane isn't working.

 

Or maybe the tubing just isn't set up right on the flow restrictor.

 

I'm surprised that the tap water where you are is only 25.  Mine, in Gaithersburg, was 150 or so without RO/DI.  

 

[Reeling Reefer]

tubing all is right and flush valve is right 

[Stephen]

Have you looked at some of the videos on Bulk Reef Supply about installing and tuning RO/DI systems? 30 psi is too low. Membranes are much more efficient at higher psi. I don't think I've ever seen a membrane that suggest less than 50 psi as minimum pressure. The 30 psi you have right now is not enough pressure to force your source water through the membrane efficiently. That's the reason you're getting so much rejection water. Up the pressure, lower the rejection rate. You need a booster pump and if you're still worried about wasting water add a second membrane.

 

Reverse Osmosis Accessories

[menglish]

So, at first i was thinking that your flush valve was turned to flush the membrane, so recheck that. 30 psi is very low, a booster pump is needed. I have anywhere bw 60-90psi. 

The other think i have is a 75g upgrade kit from BRS. Now my waste is significantly reduced. 1g waste for ever 1g RODI produced.

You can get a 1 g jug and just measure exactly what your waste and production ratio is.

My waste water, i put it in a 75g storage bin outside and i use it to water the lawn/garden.

 

Good luck

 

Milton

[AndrewRyan]

I debated jumping in on the topic, because others have said it already.  I have to say is that I think a booster will help you not only produce less wastewater but also (as a result?) produce RODI water faster.  I have the same unit as you and also have terrible water pressure at my house.  I was measuring 20-30 PSI at first install.  I got a booster two days later and it brought me up to 60-70 PSI instantly.  For the $100 cost, I can't imagine not having one now.

 

For what it's worth I was hovering around 45 TDS out of the tap.

[Reeling Reefer]

what booster pump did you get ? 

[Origami]

On 12/6/2020 at 6:53 AM, Reeling Reefer said:

I am at like a 20 to 1 ratio

 

In normal operation, you expect a waste:pure ratio of 4:1 or 5:1. 20:1 is very poor. I suspect that your low pressure has a lot to do with it. The Dow Filmtec 75/100 gpd membranes that we see a lot of in the hobby, for example, cite 30 psi at the very bottom of their pressure curves with the lowest production. Low pressure also causes large amounts of waste water.

 

A booster pump is needed or some other means of increasing pressure. 

 

On the plus side, if you're really getting 25 ppm TDS, that's really low and your DI resin should last a very, very long time if you have a decent membrane installed.