[lukeg]

Built myself a 4040 set up about 3 wks ago, all was running really well tds in 457 out 21  at a ratio of 1 litre pure to 1.25 waste. I mounted it on 16mm board but made a mistake by using plastic waste pipe clips to secure ro as I found out when the continuous light vibration snapped both the clips and ro fell to floor and one of the ends popped off and membrane slid out a little.

So replaced broken fittings and mounted it using proper bolt through straps. Started ro running,  tested water and the lowest I can get it is 40 so took membrane out checked brine sill and all looks ok. Put back together and retested and still the same also tested tap water again and its still 457

Anyone have any ideas why tds has doubled and is this an acceptable tds before di, its doing my head in so any help would be appreciated

[luther1]

Adjust the waste. 4040 Tds shouldn't change in 3 weeks

[lukeg]

Should of said I have been adjusting it and it never gets any lower

[king marko]

Just to make sure... You have flushed it? And you did put the membrane back in the correct way after you'd taken it out?

[luther1]

How long are you letting the water flow when you've made an adjustment before you take a new Tds reading?

[lukeg]

It is all in the right way and seals all In  place double checked , flushed it for an hour before first reading then everytime adjusted left it 10mins before taking new reading

[Ian Lancaster]

Is it possible the seal round the membrane was slightly damaged when it fell out?  Unless the seal is perfect, a small amount of 'raw' water can by-pass the seal and contaminate the product (pure) water.  I had one where the edge of the seal curled over when I put it in - I didn't notice at the time but the TDS leapt up.  I took the membrane out to check and found the bent seal.  Straightened it out and put some vaseline on it - put it back in and problem solved.

[lukeg]

I have the mebrane in out a couple of times again this weekend and checked the seals, they all look ok and are all well vaselined up, yet still the same, i'm going to try another membrane to see if i have damaged mine when it fell out even though there is no apparant damage it might be internal