[JamesLord]

We are having problems with getting our parts per million down.  This has never happened before so would welcome thoughts.  it is an ionic system but we have a blue vessel for the resin.  Currently I cannot get the Parts per million lower than 6 and normally get it to 0.  The water going into the vessel is 10 and coming out it 6.  I have emptied the tank of all its water.  done a backwash and tried 3 lots of resin, (1 from a new bag) but it still wont go below 6.  anyone got any idea as Im not a bit baffled and don't want to loose any more days work.

thanks

James

[chris turner]

Replace the  head of the resin vessel m8.
I recently had a similar problem, couldn't get my tds below 2 even with new resin.
Iv replaced the entire resin vessel and now back to 0.
Much cheaper to replace the head though, about £30.

[Tom White]

I've got a cheap 'something per day' RO (I can't remember what, I've had it for about 9 years now) which produces zero TDS water.

However I'm happy with working up to a TDS of 15.  Some guys are happy to work with a lot higher TDS.

[SeanK]

Firstly at 6 you wont have any problems cleaning so you shouldn't lose any work.
Next remove the head/tube and connect it to a tap then watch to see what way the water is flowing, it should mostly be coming
from the bottom of the tube. ( connect to the water in side )
If this isn't the case then the tube is blocked and you need to flush it out.
There are only two reasons why a DI bottle doesn't work ether the resin is faulty or the water isn't being filtered through it.

[JamesLord]

thanks we will give these ideas a try.  the resin vessel is only a few months old so hope not to have to replace the cap

[Ian Lancaster]

Try calibrating your TDS meter - they're not infallible, I've had ones that were several ppm adrift from new.

Also as others have pointed out, "zero ppm" isn't some magic formula, it's just an artificial way of describing the purity of water, it just means that water may be of pure enough quality to give a spot free finish.  The actual "ppm" at which that result is achieved can only be ascertained by trial and error but it certainly doesn't have to be 0ppm.

[CLEANCARE WC]

Try calibrating your TDS meter - they're not infallible, I've had ones that were several ppm adrift from new.

Also as others have pointed out, "zero ppm" isn't some magic formula, it's just an artificial way of describing the purity of water, it just means that water may be of pure enough quality to give a spot free finish.  The actual "ppm" at which that result is achieved can only be ascertained by trial and error but it certainly doesn't have to be 0ppm.

Let this be our go to quote when we next have a debate about what TDS is possible to work with.

[AuRavelling79]

You might want to sort it but you'll have no problems at 010 whatsoever.

[jk999]

I used to change mine at 001 for about ten years then I bought a new ro it wasn't as good as the old one and seem to go up to  015 really quick so I kept a check on the windows been as high as 018 no spotting at all so 006 you should n t have any problems  at all 

[Richard Stevenson]

You can have spotting if you have 00 or 18 or 25. Its as much to do with the frames as the tds reading.

[SeanK]

You can have spotting if you have 00 or 18 or 25. Its as much to do with the frames as the tds reading.

But that's a different issue, we are talking about how low does the tds have to be before the water is no longer usable.
Some think anything above zero will cause spotting which isn't the case.