Question regarding soda ash

[Tink]

Soon I'll be moving into a new place that has well water. They have a soda ash injection system installed just after the well pump to raise the pH of the water before it goes through the plumbing. My question is this:

 

I use a RO/DI system to filter my tank and top off water, and must continue to do so due to the new water being high in NO3 (7.4mg/L). Will the soda ash injection system serve to wear out my filters sooner? I would imagine the RO/DI will just filter it all back out, thus making the system work that much harder.

 

Anyone have any experience with this sort of situation? Thanks

[Origami]

The carbonate and the hydrated sodium ion will, for the most part, be filtered out by the RO membrane because they're pretty large in comparison to a water molecule. There's a possibility that, if the pH is sufficiently high and calcium is high, there may be some precipitation at the membrane surface which will accelerate clogging of the RO membrane (and shortening it's life). Frequent flushing of the membrane may help keep the membrane clear.

 

Many of the AWI RO/DI systems that I've seen (and had) have a fast-flush capability. If you make your RO/DI water manually, make sure that you do the fast-flush shortly after finishing making a batch. This should help prolong membrane life.

 

You also may see some reduced life from your DI resin, but I think that this will be secondary and of less concern. For those of us on well water with low pH going into our RO/DI systems, we suffer from rapid depletion of the DI resin which can get expensive. Your soda ash system may be a blessing. Time will tell.