To obtain the result you want, they softeners would need to be placed in parallel, and the water diverted away from the one regenerating and to the one in service, effectively emulating what a dual-tank softener does. Adding another softener in series will buy you nothing.

Do you use water 24/7 in your house?

Thanks for the reply but I don't understand.
If I place the second water softener down stream from the first won't it treat the hard water that is being bypassed by the first softener?

Yes and possibly no. Most decent softener valves now will simply bypass hard water to the system during regen, but some (particularly older models) will pass the regenerant into the system during regen. If you have one of those, forget it. So: What specific softener do you have and how old is it? And, do you really use water 24/7?

If you install a softener downstream, you will incur several issues:

1. The second softener would have to have water running through it at all times the first softener does, but most of the time it would not be doing any actual softening.

2. The second softener would need only a very small capacity since it would really only be needed during regen, about 2 hours per weeks on an appropriately sized softener.

3. The second softener would need to be the same size as the first softener, however, regardless of capacity needs, in order to avoid unnecessary pressure drop.

4. The second softener would need to either be regenerated just as often as the 1st softener OR use a more sophisticated valved that would allow a periodic backwash without regeneration.

5. If you do it right (and that's a pretty relative term since two softeners in series isn't right to begin with) it would likely be less expensive to sell your existing softener to someone that could use it (provided it's a good, industry standard unit) and purchase a dual-tank system.

6. Two separate systems = twice the maintenance

7. You would have no way to ensure that both softeners never regenerate at the same time, unless you want to have one regen during the day.

8. You would have to have two brine tanks as well, to ensure you always regen with a strong brine.

In short: It's a really silly way of attempting to reinvent the wheel, an inferior wheel.

This post was edited by aliceinwonderland_id on Sat, Feb 15, 14 at 18:52

If you have a contemporary softener that is demand initiated it will regenerate at 2AM and you'll have unsoftened water for the 90 minute or so duration of the regeneration.

If you're not up and using water at 2AM then you have no hard water to deal with. On computer controlled softeners that regeneration time can (usually) be changed if there is a more convenient time to regenerate when there is no water usage.

If that doesn't suit you then get the right hardware for the job and buy a Fleck or Clack based twin resin tank softener and sell your old one to offset the cost.Fleck based t\wins are usually 1/3 the cost of Kineticos and will give you the same performance with the added plus of the ability to get parts almost everywhere and tech info is free to download.

I was a big fan of the twin resin tank design but after living a long time with a correctly sized and efficiently set on demand softener I can only count three times that I was up and flushed a toilet during regeneration. Even with an old tech toilet that's 5 or 6 gallons of hard water getting into the plumbing and being diluted by the soft water already in the pipes.

Ubless the thought of 5 gallons of hard water getting into your plumbing on the rare occasion that you need to go and flush during the softener regeneration I'd look for something else to worry about.

And BTW, as well as Kineticos operate they have their own anomalies to worry about.

I have an issue with soft water at a school kitchen.

There is a commercial dishwasher with a dedicated 45,000 grain softener and water heater. There is lime build up on the DW. The water has been tested multiple times by the dishwasher company and it always comes back as soft.

As I understand a typical softener will lower hardness to 0-1 grains per gallon (1 grain = about 17 ppm) since the wash cycle is 155 deg F and the rinse is 180 deg F, my guess is that this residual hardness is precipitating

Will a second water softener in series remove this remaining hardness? I know Reverse Osmosis will remove this, but I am not aware of systems sized for this application