>I am currently having trouble with our DI system.  I have changed the carbon
>and replaced the resin in the anion column.  I also regenerated the cation
>column.  The trouble I have is that the microsiemens (microhms) reading will
>stay below 20 for only a few minutes and then it shoots off the meter.  Any
>comments or suggestions would be greatly appreciated.
>
>Thank you,
>
>Mark Wilkins
>

Mark,

There are several things to check.

First, check the pH coming out of the system.  If it is high, the cation
column is not regenerated, if it is low, the anion column is not regenerated.

Second, did the system add all the acid/caustic it was supposed to when it
regenerated?

Third, check for proper rinsing, is the outgoing pH very high or low (>13 or
<1).

Are you rinsing with DI water?

Are you counterflow rinsing?

If these are 4" column tops, check the column tops to make sure the riser
pipe did not pop out.  This will cause the regenerants to bypass the resin.

Have fun,

Bob Mesick

Remco Engineering
Environmental Water and Wastewater Treatment Systems
Home: http://www.remco.com