[Dave Willis]

I have DI vessels in tandem, my tds keeps creeping up and so far I've blamed poor quality resin.

However, when I go to empty the first vessel it's dry, no water in it, how can this be? The plates look clean so I guess the rubber isn't tight enough on the riser tube anymore?

Any ideas?

[ChumBucket]

Are the riser tube strainers clear? They can get blocked with resin beads, an old tooth brush is a good way to clear this.

[nathankaye]

Take the riser tube out your di vessel and connect water to the outlet rather than the inlet and flush it. This should clear any blockages.
As obviously its by passing resin altogether. Did you over tighten lid??
Hows the 2nd di, is that working ok?

[Dave Willis]

No blockages. Might wrap a turn of tape around the top of the tube.

[Arnold Palmer]

Did you have it flowing in the right direction?

[Dave Willis]

Yes, 'tiz nearly ten years old now, maybe time for a new one - I haven't spent a few thousand with Gardiners this year so I'll add it to the next lorry.