Welcome to the UK Window Cleaning Forums

Starting or own a window cleaning business? We're a network of window cleaners sharing advice, tips & experience. Rounds for sale & more. Join us today!

Ro help( again)

Dan Paton

Active member
Messages
257
Location
Glasgow
Guys I attempted to set up an old ro system today. I changed the membranes and filters. Then started running water through it. I started flushing it and I've got water coming out 2 pipes as I should. There's a couple of problems though.3 hours later the water is coming out at a tds of 280 but my tap water is only 260ish. The water coming out of both tubes has the same tds. I'd have thought one would be higher than the other. Any ideas ??

Sent using the Window Cleaning Forums mobile app

 
You got a pic of it set up? With all the connections in view?

Maybe you've put it together wrong

 
I'll go take a video Dave. It's definitely me that's put it together wrong but I just don't know where.


Sent from my iPhone using Window Cleaning Forums

 
Sounds like you got the waste going through both as it is higher than the input tds

 
Still trying to work out what is connected to what on that vid

This is how mine looks 

1 waste

2 pure to di

3 prefilters to membrane

Note how the waste and pure outlets are positioned differently on the membrane housings.. that is standard on all those type housings

Have you got a pic where i can see iy all at once like my pic as it looks like it is connected up weirdly

Some are sold connected so 1 membrane feeds the next etc which is a lot less efficient

20170716_201510.jpg

 
It looks the same as yours on the left Dave. Green is waste and blue is pure. The green one leads to the valve I turn to flush the system. Is that right ?
7215d9086ce159dce7876496a07170e1.jpg



Sent using the Window Cleaning Forums mobile app

 
Some things don't make sense in that pic

The green shouldn't be connected to the blue where i have circled it and also the other green shouldn't be going from the waste on 1 membrane to the input on another membrane

You would be better off disconnecting it all and starting again following my pic closely 

The waste valve can be set up like mine not on the unit

@spruce any idea why it would be set up like this?

20170716_204219.jpg

 
Last edited by a moderator:
Still trying to work out what is connected to what on that vid

This is how mine looks 

1 waste

2 pure to di

3 prefilters to membrane

Note how the waste and pure outlets are positioned differently on the membrane housings.. that is standard on all those type housings

Have you got a pic where i can see iy all at once like my pic as it looks like it is connected up weirdly

Some are sold connected so 1 membrane feeds the next etc which is a lot less efficient

View attachment 10698


The way you have set it up makes sense to me and was the way mine came set up.

@Dan Patonis got added confusion with his switch off valve.

There are 3 ways to connect an r/o up.

1. your way.

2. Firstly all the pure outlets are joined together to go the either the di vessel of the storage tank. The water comes in from the prefilters to the first membrane. The waste from the first membrane goes to the inlet of the second membrane. The waste from the second membrane goes to the inlet of the third membrane. The waste from the third membrane goes to the restrictor and then to the drain.

The problem with this is that each membrane has to remove a higher concentration of tds than the previous one inline. You usually end up with a premature demise of the last membrane but will need to replace all three. Water saving is a benefit.

3 Again, all the pure lines are joined together as per the previous 2 ways.

The inlet from the prefilters is divided into two and fed into the first 2 membranes. (So the first 2 membranes will be getting water of the same tds.) The waste from both the first 2 membranes become the supply for the third membrane. The waste from the third membrane goes to the restrictor and then onto the drain.

As you pointed out @Dan Patonhas mixed his hoses up and needs to start again. The waste of these housings is off center and the pure comes from the center.

 
Last edited by a moderator:
Cheers lads. Just for the record it was already set up like that. I basically just plugged it in. There's one bit I don't get. On the end of the blue tube where I have the water coming out. There was a check valve attached. I took it off as I couldn't figure out what it was for. The water was going into the system but none coming out.


Sent from my iPhone using Window Cleaning Forums

 
What is the point of the 3rd way you mentioned @spruce ?

I even took the second tap off and put the waste restrictor back on temporarily to show it was waste in the pic.. usually it is a second inline tap that i have set where i want it

 
What is the point of the 3rd way you mentioned @spruce ?

I even took the second tap off and put the waste restrictor back on temporarily to show it was waste in the pic.. usually it is a second inline tap that i have set where i want it


It's was the way a local windies came connected up. I don't know why they did this but some say it is the way of reducing waste water but they never offer any proof to substantiate their claims.

I never tested it myself as it never made sense to me. I did analyse all 3 methods once and all I could come up with is that by feeding the next membrane from the one prior would reduce the number of JG T pieces required. That would either mean that the r/o was cheaper to assemble = more supplier profit or more competitive selling price or both.

Ro_Man prefer the second method of connecting their systems up.

http://www.ro-man.com/instructions/RO-MAN Reverse Osmosis manual for 200 and 300 GPD systems.pdf
If a membrane produces 150gpd then 3 membranes are going to produce 450gpd. I can't see how connecting them up differently will save waste water. If you want to save water you just restrict the amount of water going to waste a little more. RoMan restrictors result in a 3 waste to 1 pure ratio. If your water is relatively soft to medium you can get away with a 1 to 1 ratio. That's a saving of 2 liters for every liter produced.

Excuse me for seeming a little cynical but it comes with age. The way RoMan connect their systems up (option 2 on previous thread) will really tax the third membrane. As its working harder having to remove a higher tds, will it fail prematurely? One of the American fish keeping forums confirms this. As window cleaners we have a formula that tell us when we should start to consider changing membranes. And we nearly always will replace all 3 together. If so does this mean that suppliers will get more membrane purchases connecting membranes in Series rather than Parallel?

This reminds me of another supplier who doesn't fit a carbon filters to their systems as they don't believe we have sufficient chlorine in our tap water to justify the need for a carbon block. No one else agrees, but they are assured of premature membrane failures meaning more repeat sales from the unwary.

It would be interesting to hear what others have to say on this.

. 

 
Last edited by a moderator:
Nothing worse than getting the pipes mixed up, I have happily disconnected all mine in the past changing some membranes thinking I would remember were they all went I was totally wrong, Spent ages sorting it out as I didn't have a clue but thankfully with the help of Doug Atkinson spent time on the phone and emails to get me sorted. 

Switched membranes the other week and did one by one and their was no need to disconnect all the pipes, Just removed the pipe from the threaded end of one membrane at a time and did the switch one by one. 

 
Before i knew what i was doing i used to take a pic on my phone before dismantling it

 
Mine came second hand. All I basically did was change membranes and filters and turn the water on. Why it's plumbed in that way is beyond me. I'm going to give it a go later. If anyone has a diagram it would be most helpful.


Sent from my iPhone using Window Cleaning Forums

 
Do it exactly like my pic if you have enough connectors

If not do it like the diagram in spruce's link he posted and order some t pieces and change it once you get them or you will eventually knacker the last membrane in the series

 
Back
Top