# RO help



## Nick16 (19 Nov 2013)

hi all, 

i have an RO unit from osmotics, and have set it up as portable (3 ball valves, one on each of the lines so i can block of a line and drain it etc. 

my question is that i thought you always had to have the (black) waste water line open, which meant that i was getting 10-15 litres of waste for every 1 of RO. I understand that if you turn the existing valve that comes with the system it does not filter anything and diverts it all down the waste pipe. 
however if i block of one of my new ball valves which is on the outlet side on the unit, i get 0 waste water and still the same out of RO. (obviously a bit more back pressure but not alot) 

should i leave the waste water line open and accept that i will have loads of waste, or should it be shut off, so all that comes out the system is RO

cheers


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## ian_m (19 Nov 2013)

Sounds like you have the flow restrictor missing, which is why you are getting 10-15litres waste for every 1l of RO ?

You remove/bypass the flow restrictor to flush the unit.


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## Nick16 (19 Nov 2013)

flow restrictor is there. il upload a snap


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## Nick16 (19 Nov 2013)

flow restrictor there, my water is 50psi which isnt high but should be enough.

water water is a gentle flow whereas RO is a steady drip drip

i can shut of the ball valve on the waste line (not the one on the top of the unit) which means only RO comes out, but still at a drip drip


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## Nathaniel Whiteside (19 Nov 2013)

That's not a flow restrictor,
that's a Flush valve isn't it?

I turn mine to flush the system then fully close it again and still get waste water.
It should be in between the bottom two and top two filters.

A flow restrictor is a piece of white plastic ;

Flow Restrictors

Which should be placed where you have your flush valve now.

Edit:

Correction, just seen you have a flush valve in the correct place. Middle of unit.


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## Nick16 (19 Nov 2013)

yeah and the flush valve is there in the middle at the top on the opposite side to the flow restrictor and thats in the correct position. 

its taken me about 4 hours to get 13 litres of RO which seems rediculously slow. 50psi isnt awful its the minium they recommend but shoulf still be fine. i was expecting it to take an hour to fill a 25 litre container, not 8 hours!


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## Andy D (19 Nov 2013)

Nick, I have the same system set up in the same way with the same pressure and mine takes about 8 hours to fill 25 litres.

I think you have set it up correctly. Just takes a lot longer with a lower pressure. Temp can also be a factor too.


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## Andy D (19 Nov 2013)

Saying that I think my pressure is actually lower than yours. Will check later when I am home...


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## ian_m (19 Nov 2013)

50psi (3.4 bar) is rather low, I suspect at that low pressure you might need a smaller flow restrictor, to increase back pressure. This is why you sometimes have buy the flow restrictor as a separate part to match your incoming water pressure.

Some RO units quote 120litres/day at 6bar. Working backwards for your 3.4 bar gives 3.4/6*120 -> 70litres per day -> 22litres in 8 hours, almost matching your figure, assume 120l/day unit.

Might be completely wrong, my coat is ready for me to leave


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## Nick16 (19 Nov 2013)

nah that all tallies in mate. i assumed i had set it up correctly, i just hoped i wasnt missing a trick. as i thought then, its having pants water pressure! 

it wouldnt be too bad when its W/C time as i would only need a small amount. (150l tank, with an ex1200 fully matured and only a few CRS as stock. i could probably get away with 10% weekly or even 20% every 2 weeks) 
but im soon to be filling the tank so i need alot of RO! (will cut with tap) 

cheers chaps!


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## ian_m (19 Nov 2013)

You need a booster pump or have 8bar water pressure like I have. I can squirt water from the hose pipe over the house and wash (well wet) the cars from back garden pressure is so high.


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## sa80mark (19 Nov 2013)

One thing I used to do was to run my ro unit at night I dont know if its the same everywhere but my water pressure was approximately 1.5bar higher at night I presume this is because no one else was using water at night ?


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## Andy D (19 Nov 2013)

sa80mark said:


> One thing I used to do was to run my ro unit at night I dont know if its the same everywhere but my water pressure was approximately 1.5bar higher at night I presume this is because no one else was using water at night ?


 
I think you could be right. My shower has a lot more pressure on the weekend mornings than it does during the week.


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## Spnl (19 Nov 2013)

You need a booster pump.
I have an Osmotics 50gpd system, mains pressure less than 40 and it was producing just a drip. Brought their booster pump, and now takes about 1.5-2 hrs to produce 25l, waste is much less, and tds went from about 18 without pump to about 8 (mains is London water at about 330).
If you are getting no waste, there must be something wrong?


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## danmil3s (19 Nov 2013)

i get about 25l in 8 hours which is fine for my tiny tank, but if that experiment works i'll think about using RO on my disasters  large tank. so I'll be interested to know how you get on if you do buy a pump.  it looks relatively simple to set these things up so the shut of automatically. you might just be able to top your tank up over night.


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