Water softener/rodi?

[RobBaglieri]

I am running a water softener before my RODI system. The system consists of a sediment filter, then the softener resin beds and then the RODI system. I am not an expert but I am pretty certain that the softener bed does not add anything to the water.

 

[AZDesertRat]

A softener adds sodium or potassium in exchange for the calcium and magnesium it removes via ion exchange.
Since the exchange is not an exact 1:1 ratio the TDS will go up slightly in most cases.
You are much better off though as membranes are designed to remove salts and it is much easier on them than removing calcium.

 

[RobBaglieri]

I have two ion exchange resin beds in paralell. One is used while the other is being regenerated with salt water. The salt water is rinsed to drain the the beds automatically switch. Not sure if all softeners are designed this way. I suppose there could be salt left in the resin bed after regeneration. I have never tested it. I had the whole system installed when I moved in to treat very hard well water. I am very familiar with RODI and WFI generation, but only on the grand scale at work.

 

[AZDesertRat]

Yes, there is salt left behind. This is the reason doctors tell you not to drink softened water if you are on a low sodium diet.

 

[monkeyCmonkeyDo]

On a tap water drinking Filtration system yes maybe but not on a 4-6 stage rodi saltwater aquarium water filter
If you doubt your filters capabilities I recommend air water and ice as they have the best filters available imo.
D

 

[monkeyCmonkeyDo]

You don't need a whole new unit. Just swap the filters with some from them.
D