[Filllllll]

Its been 11 weeks and the reading out from my 25litre resin vessel has now gone up to 001.
tds 'in' is only 002.
Surely it should last longer!! And yes I have back flushed the vessel & I got 000 for a day only.

Any suggestions as to why?
p.s. My system is: Tap water 430 tds-merlin 33tds-1st resin vessel 002 tds(old resin)-2nd resin vessel 001 tds-tank.

Cheers,   Filllllll

[Alex Gardiner]

The most likely reason is that the water has formed a channel through the resin and is only fully using a small part of the available resin. Give the resin canister a good long shake up, do this every time it rises, you will be amazed at the results.

Alex

[Londoner]

You don't say how much water you have put through the resin in those 11 weeks However, I think Alex has hit the nail on the head.
Resin only takes out calcium, your tds reading of 001 doesn't have to be caused by calcium anything dissolved in the water will give a TDS reading

[edd]

my tds out of ro is 2/3 ppm resin has lasted ten months so far possible lasts another ten i make around 500 ltr daily 40/40 ro 10inch particle and 10inch carbon 25 ltr di with the tds 000 are you sure the resin is not softner resin ??
dowex seems too be the best or mb400 purlite

[edd]

just remembered something someone else did and not put the long riser tube back
in the di vessel so it only had the top bit in and his resin only lasted a few weeks
i hope this helps we all make mistakes Edd

[Filllllll]

Thanks for your thoughts.
Input through the resin is around 300 litres per work day.
The resin is the proper stuff.
Also,further to Alex G point about channeling,I had given the vessel a good shake and also back flushed.
By the way, before I used 2 di vessels the input straight in from merlin was around 33 tds and the resin would last approx 8 weeks.

Cheers, Filllllll