The Beauty of Soft Water

[SteamyTea]

On 3/23/2018 at 07:39, 8ball said:

Next week I start my mission on finding a decent water softener.

She has a softener made by Kinetico.

It is the second softener she has had in 30+ years and I think this one is over 10 years old.

[8ball]

39 minutes ago, SteamyTea said:

She has a softener made by Kinetico.

It is the second softener she has had in 30+ years and I think this one is over 10 years old.

 

I had my eye on one of those on Ebay, it was used for 6 years. I ended up fussing over it that much trying to decide that I missed the end of the auction

 

Still trying to decide to go used or new, the used ones go for about £350 - £450 and new around the 1k

[SteamyTea]

I think my Mother's was around a grand.

Thinking back, the old one was damaged when they refurbished her kitchen.  So not a fault as such, just bad fitting.  She puts slat granules in it rather than tables, not that it should make any difference.

[Jeremy Harris]

On 26/03/2018 at 09:36, jack said:

Me too. 

 

The plumber and I couldn't figure out how a properly functioning softener could cause corrosion of stainless steel when we saw the "no softened water" line in the instructions. I called them to ask for more info and was told that no warranty claims would be considered if softened water was used. Between that and not having time to do any research, we just went ahead and plumbed in unsoftened. 

 

I just had a look on their website and it includes the following:

 

If choosing a water softener, it is important that you choose a system that does not remove all the minerals from the water, leave excess salt behind or reduce the pH-value of the water below 7 as the water will become corrosive otherwise. Reverse osmosis systems may not be suitable and are not recommended. Hydrogen Resin Exchange systems could rapidly change the pH valve of the water and are not recommended. Be aware that Sodium Resin Exchange systems can cause excess salt in the water which will cause corrosion on the Quooker tank.

 

But then, Harvey water softeners says the following:

 

Yes you can absolutely use our system with your Quooker (or other) hot water tap. Our technical director has verified that softened water from one of our units is fully compatible.

 

My best guess is that Quooker is oversimplifying the situation for convenience, rather than giving tailored advice based on different softeners. 

 

 

As we needed to get our water tested anyway (as I have means of getting this done cheaply, but unofficially!) I had samples of both the unsoftened and softened water tested.  These were the results:

 

 

 

All the values in the softened water were well within the  UK acceptable limit, and in the case of the sodium ions that were substituted for calcium and magnesium ions in the softener, the softened water is less that half that allowed from ordinary UK tapwater.  The pH dropped a tiny amount, but is still just alkaline, so there is no corrosion risk from that.  For comparison, the pH of the water in Cornwall can often be around 6 or so, so significantly more acidic than ours, even after treatment.

 

[Dreadnaught]

Off topic. @JSHarris Its interesting that the one measure that is closest to being at the limit is nitrate. Inorganic fertilisers in use around you?

[billt]

1 hour ago, 8ball said:

Still trying to decide to go used or new, the used ones go for about £350 - £450 and new around the 1k

 

New ones are available for less than £400.

https://www.screwfix.com/p/bwt-compact-metered-water-softener-10ltr/45059

or

https://www.wickes.co.uk/Wickes-E10T-Fully-Automatic-Robust-Water-Softener-Unit/p/421700

 

and no doubt others.

 

They will be timer operated and need an electricity supply but they will soften water just as well as the expensive ones.

 

[richi]

1 hour ago, billt said:

They will be timer operated

 

Looks like the BWT/Screwfix one is metered, so probably a much better idea.

[Jeremy Harris]

2 hours ago, Dreadnaught said:

Off topic. @JSHarris Its interesting that the one measure that is closest to being at the limit is nitrate. Inorganic fertilisers in use around you?

 

 

We draw water from an aquifer that's so far down that the water we're using probably predates the use of man-made fertilisers.  The hydrologist reckoned it would be 200 years old or so, and that fits well with the fact that there are no seasonal variations at all in the standing water level - the pressure in the aquifer is high enough to raise the level in our borehole to around 35m above the level of the Lower Greensand, which tend to support the view that it's "old water" that is now under significant pressure within the aquifer itself (roughly around 3,5 bar).  Had our ground level been around 5m lower the borehole would have been artesian, with water freely flowing out of the top.

 

We're in the bottom of a valley where the stream has eroded the deep layer of overlying chalk and the Upper Greensand formations, and is now running along the exposed Gault clay.mudstone layer.   The water that feeds this stream comes from many springs that originate along the base of the chalk and which flow through the relatively thin Upper Greensand formation, and that has no iron in it at all (untreated, the water from our borehole has over 200µg/l of iron in it), but does have a lot more calcium, which it's picked up from the chalk.  The level of the stream is very variable with both the season and local rainfall; right now the stream is as high as I've seen it in a fair while, most probably because of the long period of rain we've had recently.

 

It seems probable that the nitrates in our borehole water may well come from a natural source in the Lower Greensand aquifer, as there's a ~40m thick layer of Gault clay/mudstone over the top of it that acts as an aquatard, preventing surface water from percolating through directly.  The Lower Greensand aquifer that we are drawing from is hydraulically isolated from the two similar larger Lower Greensand formation aquifers that supply water to the London and South East, those within the Hythe and Folkestone formations, well to the East of us.  The Lower Greensand in our area overlies hard Wealden sandstone that is at a depth of around 51m from the surface and below that are the Purbeck formations that are closely related to the oil-bearing shale formations further to the South West and that have been producing oil from onshore wells in Dorset for a few decades now.

 

 

 

 

[Dreadnaught]

1 hour ago, richi said:

Looks like the BWT/Screwfix one is metered, so probably a much better idea.

 

@richi are you drawing a distinction between metered and timed softeners? I would be interested in your reasoning. I have been thinking about the same subject.

[richi]

1 minute ago, Dreadnaught said:

 

@richi are you drawing a distinction between metered and timed softeners? I would be interested in your reasoning. I have been thinking about the same subject.

 

I'm far from the expert. In fact, most of what I learned came from @JSHarris. But a simpler, timed softeners regenerate overnight, whether it needs to or not. Whereas a metered softener will skip regeneration if not enough water's been used.

 

(The regeneration process is mumble-something-to-do-with-ions-mumble-resin-squirrel.)

 

Ergo, timed softeners can waste salt, water and electricity. I suspect overuse of salt might also cause excess sodium in the water at the taps, but don't quote me on that.

[billt]

Those that want to sell metered softeners will exaggerate the supposed benefits, much more profitable.

 

You set up a timed softener so that it regenerates at intervals to suit the hardness of the water and the amount that is typically used. If you set it up wrongly then you can waste salt (and water, but that's trivial). If you set it up correctly, and there aren't huge variations in your usage patterns, then I expect the difference in salt usage is negligible. If you worry about the amount of electricity used by an electric clock (< 1W), then I think you have problems of perspective.

[Jeremy Harris]

21 minutes ago, richi said:

 

I'm far from the expert. In fact, most of what I learned came from @JSHarris. But a simpler, timed softeners regenerate overnight, whether it needs to or not. Whereas a metered softener will skip regeneration if not enough water's been used.

 

(The regeneration process is mumble-something-to-do-with-ions-mumble-resin-squirrel.)

 

Ergo, timed softeners can waste salt, water and electricity. I suspect overuse of salt might also cause excess sodium in the water at the taps, but don't quote me on that.

 

In essence that's spot on.  The process is pretty simple, chemically, in that the ion exchange resin swaps calcium and magnesium irons in the incoming water for sodium ions that it has obtained from being regenerated using salt (sodium chloride).  During regeneration, sodium ions are swapped out in the resin for the stored magnesium and calcium ions, discharging chlorides of calcium and magnesium down the drain.

 

The ones that are metered tend to use a lot less salt for those whose water usage is variable, so can be a fair bit cheaper to run.  The ones that are timed may well waste a lot of salt by flushing brine through the ion exchange column when it doesn't need it.  If you use roughly the same amount of water evey day of the week, all year around, then a well-set up timed softener may not cost any more to run than a metered one.  However, if your water usage tends to vary a bit then the greater the variation the more salt will be wasted.

 

Over-use of brine doesn't do anything other than waste salt, as once the ion exchange resin is charged the excess brine just flows down the drain.  The valve head flushes any remaining brine in the column to waste with incoming water anyway, so salt can't normally ever get into the house pipe work***

 

 

*** I mentioned normally, but on some units if the outlet pressure from the softener momentarily exceeds the inlet pressure during a regeneration (say from an anti-water hammer accumulator) then it is possible for brine to get into the house pipe work, due to the way the valves operate.

 

 

[richi]

15 minutes ago, billt said:

If you set it up correctly, and there aren't huge variations in your usage patterns, then I expect the difference in salt usage is negligible. If you worry about the amount of electricity used by an electric clock (< 1W), then I think you have problems of perspective.

 

Personally, I estimate our daily usage varies by around ±50% -- not including external taps, which I'd plumb from the pre-softener feed. (And anyway, this is BuildHub; we're obligated to have problems of perspective!)

[8ball]

47 minutes ago, richi said:

 

(The regeneration process is mumble-something-to-do-with-ions-mumble-resin-squirrel.)

 

[Dreadnaught]

2 hours ago, billt said:

Those that want to sell metered softeners will exaggerate the supposed benefits, much more profitable.

 

I tend to agree. I have come across some old-hands who service softeners who say the same. They swear by the mechanical reliability of some of the old mechanisms and say they were much easier to service.

 

One thing I am not sure about is the frequency of recharge. It obviously depends on usage. If it is daily then I can see the metered may be better if demand varies. But I had assumed that the recharge would be in the order of every few weeks, in which case demand would be smoothed and a timed softener would be adequate.

 

Personally, I am tempted to buy second-hand and larger, perhaps ex-commercial, ion-exchange vessel, so requiring less frequent recharge, and combining it with a tried-and-trusted timed mechanism. Much cheaper, reliable and easier to service. Just my tuppence.

 

Edited April 4, 2018 by Dreadnaught

[richi]

I wonder how hygienic an over-sized vessel is

[Dreadnaught]

26 minutes ago, richi said:

I wonder how hygienic an over-sized vessel is

 

Saturated brine would act as a good sterilant I would have thought. I wouldn't expect microbial growth to be significant for at least a few months.

Edited April 4, 2018 by Dreadnaught
More info here if interested: https://www.wqpmag.com/resin-sterilization

[Jeremy Harris]

If you're dealing with mains water, it almost certainly has residual chlorine in in anyway, especially in some of the hardest water areas in the South of England, so I'd not worry too much about microbial growth, especially as often the larger units will be sited outside the house, in a shed or garage.

 

As for reliability, then having stripped both a Harvey metering head and a Clack electrically driven filter/softener head, I can't say there's much in the way of reduced complexity in the motorised head, if anything it's more complex than the metered head.

 

The only known weakness with the Harvey type unit was the brine water level valve on early models, something they fixed with a re-design. 

 

It is a heck  of a lot harder to strip and rebuild a Harvey type unit, but something like changing the ion exchange resin is dead easy, primarily because it's a lot easier to lift the small twin tanks out and empty and wash them out.  The bigger units are a bit more effort to empty and refill, just because of their size, but do have the advantage of having a larger empty and fill port than the Harvey/Kinetico type.

 

I have both types, as our water filter and iron removal system uses a standard Clack softener valve running on a timed cycle.  Instead of sucking in brine on the regen part of the cycle it draws in air to re-oxygenate the inside, and it's programmed not to bother with a rinse cycle, but other than that, and not having a brine tank, it't the same as a softener.  Interestingly the Clack head has already needed a new O ring on the drain outlet - not sure why the old one failed, but it was dribbling water down the tank on every drain cycle.  Easy to fit a new O ring, but worth remembering that the Clack, Autotrol and Fleck valve heads are made in the USA, so use imperial sized O rings.  The Harvey is made in the UK and uses metric O rings.  The Kinetico also uses imperial sized O rings I believe, as that's a US design too,