[East coast window cleaning Services]

After a slog this afternoon i have run me cold fed from me loft down through the roof and into the Garden
Ive plug in the Ro Now when i tested the water it was the same as when it went in so i shut the black pipe (waste pipe) off with the lever in the pic and to my surprise 050 which i feel is fine as it was 374 when going in. Now my question is if im shutting of the waste is that any good for the unit? or im i not doing something right???

[Londoner]

I'm not entirely sure what you are doing. You need to have some waste to clear the membrane but if it gets better when you shut it off it sounds like all your pressure is going down the waste and you need a flow restricter to create a back pressure. RO units are very sensitive to pressure.
Who supplied it? you need to talk to them 

[JM123]

the merlin comes preset so no need to put a flow restrictor on the outlet.  Closing the waste or even restricting it anymore than normal is bad for the lifespan of the membranes.

what is your water pressure feeding into the merlin? 

050ppm out is terrible, our own merlin has always produced water at 004ppm, our tap tds used to be approx 350ppm before they changed the mains.

[East coast window cleaning Services]

think i may know what the problem is the elbow connections on the waste seem to be leaking

[Londoner]

How long has it been running and how are you measuring the tds? Often new collection tanks contain impurities which give an initial dodgy reading.

[East coast window cleaning Services]

havenbt set up with holding tank yet just tested it for 2 mins but gotta get leaks sorted out i think first

[JM123]

if you only tested it for two mins then you won't get an accurate tds reading.  When an ro is switched on the first few litres can have a high tds reading.  Try running the system for 10 mins then take a reading.

Oh if the connectors are leaking then you need to push the pipe in a little more, it will seem tight but just give it a firm push

[mike richardson]

if you have only been running itfor 10 mins it will be a high readingmine has to run for 20 mins sometimes b4 tds goes down try filling a couple of 25 ltr drums then test it the longer it runs the better the tds reading.

[chris@c.m.s]

Have you run the cold feed from a tank in the loft?
 

[East coast window cleaning Services]

No Of the mains in the loft not that stupid