Water softeners

[Tristar]

I have recently installed a Duotec 750 dual tank water softener, (non-electric, automatic regeneration) using block salt. These come in four different models depending on water hardness. The model fitted states that it caters for hardness up to 430ppm, but according to my water company website, the maximum hardness in this area last year was 264ppm, mean 260ppm (Total Hardness as CaCO3)

When I queried the use of the model supplied, suggesting that I should have had the next model which caters for hardness up to 320ppm, my softener supplier says that the hardness figure quoted by the water company does not include the effect of magnesium in the water, which takes the total hardness to over 300ppm average (which is still within the range of the next model). The water company water quality report does not mention magnesium, although it seems to include every other known chemical.

I am concerned that, if the model supplied is regenerating more frequently than necessary, I will not only be using too much salt, but will also have more sodium in my drinking water, as the supplier insists that I do not need a separate drinking supply, as the level of sodium in the water after softening is still below the recommended level. (What is that level? I've seen 150mg/l and 200mg/l). However, I note that all sites, including DWI, still recommend a separate drinking water supply.

Having been unable to speak with anyone at the water company who knows anything about this issue:

1. Can anyone tell me the limit for sodium in drinking water?
2. If I change my softener for the 'smallest' one that only caters for hardness up to 230ppm, wheareas my average is 260ppm, is that likely to be very inefficient?
3. If my water company quotes a total hardness (as CaCO3) figure of 260ppm(mg/l) does that include the magnesium content.?

 

[JohnD]

Not answering your question, but:

the water softeners I have had, are adjustable, so you can set them to regenerate more or less often depending on whether your water is more or less hard.

Is your softener adjustable like this? If so, no prob.

BTW the amount of sodium is governed by the amount of calcium that it replaces. The less calcium that is removed, the less sodium goes in. This is due to the ion-exchange method used in these softeners, which repaces one metal with another..

 

[Onetap]

I have recently installed a Duotec 750 dual tank water softener, (non-electric, automatic regeneration) using block salt. These come in four different models depending on water hardness. The model fitted states that it caters for hardness up to 430ppm, but according to my water company website, the maximum hardness in this area last year was 264ppm, mean 260ppm (Total Hardness as CaCO3)

When I queried the use of the model supplied, suggesting that I should have had the next model which caters for hardness up to 320ppm, my softener supplier says that the hardness figure quoted by the water company does not include the effect of magnesium in the water, which takes the total hardness to over 300ppm average (which is still within the range of the next model).

It's a base ion exchange water softener, it changes dissolved calcium and magnesium salts into dissolved sodium salts. The hardness in ppm varies around the country. A lower hardness ppm in the mains water means the softener will operate for longer before the resin is exhausted and it needs regenerating. The installer should have adjusted the setting (litres between regenerations) to take account of the incoming mains hardness and the capacity of the resin vessel.

He's talking rubbish about the magnesium. The figure is total harness expressed as the equivalent ppm of calcium carbonate, CaCO3. The watre company figures don't include magnesium because there is no magnesium. Water from a borehole in another part of the country may have dissolved magnesium, your area doesn't. It's a red herring.

The water company water quality report does not mention magnesium, although it seems to include every other known chemical.

I am concerned that, if the model supplied is regenerating more frequently than necessary, I will not only be using too much salt, but will also have more sodium in my drinking water, as the supplier insists that I do not need a separate drinking supply, as the level of sodium in the water after softening is still below the recommended level. (What is that level? I've seen 150mg/l and 200mg/l). However, I note that all sites, including DWI, still recommend a separate drinking water supply.

You won't get more sodium in the drinking water. You get 0 ppm hardness out, so you put in 260 ppm hardness in, you'll get 260 ppm equivalent sodium carbonate, NaCO3 out. The worst that will happen is that you'll waste water and salt in unnecessary regens. It should be easy to check the settings if you have the installation instructions.


As far as I know the recommendation is a separate drinking water supply. Read the installation instructions, if that's what it says, that's what you want. Accept no other.

 

[Tristar]

Not answering your question, but:

the water softeners I have had, are adjustable, so you can set them to regenerate more or less often depending on whether your water is more or less hard.

Is your softener adjustable like this? If so, no prob.

Thanks John, no info on adjustments in the instructions, and nothing obvious on the equipment to adjust, but I am sure that these 4 machines are all similar, and are merely factory set as required.

 

[Tristar]

The installer should have adjusted the setting (litres between regenerations) to take account of the incoming mains hardness and the capacity of the resin vessel.

He's talking rubbish about the magnesium. The figure is total harness expressed as the equivalent ppm of calcium carbonate, CaCO3. The watre company figures don't include magnesium because there is no magnesium. Water from a borehole in another part of the country may have dissolved magnesium, your area doesn't. It's a red herring.

You won't get more sodium in the drinking water. You get 0 ppm hardness out, so you put in 260 ppm hardness in, you'll get 260 ppm equivalent sodium carbonate, NaCO3 out. The worst that will happen is that you'll waste water and salt in unnecessary regens. It should be easy to check the settings if you have the installation instructions.

As far as I know the recommendation is a separate drinking water supply. Read the installation instructions, if that's what it says, that's what you want. Accept no other.

Thanks Onetap,

No installer or user adjustments obviously available, or mentioned in literature.

I had my suspicions about the magnesium statement.

Yes, the literature does recommend a separate tap for drinking, however the supplier insisted that, thanks "to a change in regulations" this recommendation no longer applied" due to the 'within limits' sodium content referred to in my OP. (Hence my request for the limit) However, I am now of the opinion that this guy is a BS merchant, and his attitude had more to do with the difficulty of running a pipe across the house for drinking water.