RO/DI

Jobet · May 7, 2018

I just set up my RO/DI unit. It is equipped with the inline TDS meters. One sensor is located just prior to the water reaching the DI resin and another sensor, obviously on the finished line leading to the bucket.

Ive seen 0 TDS on the out line since i started filtering water. However on the second sensor just prior to reaching the DI resin, i initially had a reading of maybe 15 ppm and it started coming down.
Now i have 0 ppm on both sensors.
Is t normal to have a zero reading before even reaching the DI portion?

Crabs McJones · May 7, 2018

Jobet said:
I just set up my RO/DI unit. It is equipped with the inline TDS meters. One sensor is located just prior to the water reaching the DI resin and another sensor, obviously on the finished line leading to the bucket.

Ive seen 0 TDS on the out line since i started filtering water. However on the second sensor just prior to reaching the DI resin, i initially had a reading of maybe 15 ppm and it started coming down.
Now i have 0 ppm on both sensors.
Is t normal to have a zero reading before even reaching the DI portion?

Depended on your source water its possible. If you have low tds to begin with your system may be able to filter it all, but i'd still leave the DI on as a final polish for stuff the TDS meter may not be able to detect efficiently. The reason you started out with TDS and it then went down is because when you first start the filters, they don't filter as efficiently as after having been running for a bit. That is why its recommended to run your ro/di for a bit before using the product water.

K. Steven · May 7, 2018

Flush your membrane before and after making water. Flushing before will avoid sending TDS-rich water (TDS creep) into your DI resin, which exhausts it prematurely. Flushing after helps remove the deposits on the membrane and further prolong its life.

Buckeye Hydro · May 8, 2018

K. Steven said:
Flush your membrane before and after making water. Flushing before will avoid sending TDS-rich water (TDS creep) into your DI resin, which exhausts it prematurely. Flushing after helps remove the deposits on the membrane and further prolong its life.

Don't confuse flushing your membrane with temporarily opening your DI bypass.