Installed water softener and tap TDS increased

[cybrook1421]

We just installed a water softener last weekend and today was the first day that I have run the RODI. The TDS of our tap water before we softened the water was 350. Now it is 450. Is it normal for the TDS to increase because of the way water softeners work? I'm going to try bypassing the softener and making sure our house water didn't just increase over the past week instead. We use potassium chloride instead of sodium chloride, in case that is relevant.

Also, it does seem to be rejecting more based just on percentages (28 TDS from 450 vs 28 TDS from 350) and I know that the softened water is better for the RODI as a whole. So, that's a good thing.

Thanks for any advice!

 

[SpursFan]

Following. Never researched this but I belive it could increase tds.

 

[KStatefan]

I do not know the answer on the softener @Buckeye Hydro can you help? In my system using salt the TDS is the same in/out of the softener.

Your RO membrane is not as effective removing the potassium ions as sodium so your DI will have to do more work. The chart i have sows 92% for potassium and 92-96% for sodium.

 

[Buckeye Hydro Verified Sponsor]

Typically TDS pre and post softener is about the same.

Softened water is easier on the RO membrane. Hard water will deposit scale inside the membrane just as it does to your water heater and faucets.

Your idea of getting a sample before the softener, or temporarily bypassing the softener is a good idea. Maybe your source water changed. Your outside hose bibs should still be on native hard water - you could get a sample there as well.

 

[Buckeye Hydro Verified Sponsor]

If this is a brand new softener, run it through a manual regen. Make sure you have brine in the brine tank before you do this.

If this is not a brand new softener, if it were me I would next also run a manual regen and I would fast forward through the regen steps until I got the the rapid rinse. Let it go through that and see if you had brine still left in the resin bed.

 

[nereefpat]

Just to add:

Our home type water softeners work by exchanging "hardness" ions like calcium and magnesium with ions in the salt. It theoretically doesn't change the total dissolved solids by weight in the water. Now, maybe the TDS meter, which is a conductivity meter, sees a difference.

Let us know what you find out in your tests.

 

[piranhaman00]

Water softeners increase TDS but it will be easer to remove by the RO.