# Low block salt indicator for water softener



## Mcluma (8 Nov 2012)

Low block salt indicator for water softener

I have recently installed a whole house water softener system (with a separate kitchen non softened water tap and it excludes, outside tap & central heating filler)

All I can say I should have done it ages ago, its brilliant, no more scale.


However mine uses block salt and its very annoying that you frequently have to check for usage, and having the machine going empty and switching back to hard water would destroy all efforts undertaken to keep everything scale free

So is there a device that measures the salt block usage and gives some sort of optical alarm when the salt block reaches a certain level?

Rather then I start to build something, I hope that this was something that would have worried other people and a solution would be readily available


----------



## flying haggis (8 Nov 2012)

have you asked the manufacturer of the softener?


----------



## whiskywill (8 Nov 2012)

It is usual to use a vibrating fork level switch for bulk solids but a cheaper option would be to use a tilting float switch which dangles on a length of cable, sits on top of the salt tablets and is set to switch at the level which you would need to refill your salt tank.
http://www.directindustry.com/prod/atmi ... 85037.html or £5 on eBay http://www.ebay.co.uk/sch/i.html?_nkw=f ... &_from=R40

For vibrating fork switches try these for a start. They are not cheap, but from past experience Hawker are the cheapest, and you will have to talk to them about the size of solids that they are able to detect. There is an Endress and Hauser Soliphant for sale on eBay for £80 but I think it's only suitable for fine or powdery solids.
http://www.ebay.co.uk/sch/i.html?_nkw=s ... &_from=R40
http://www.endress.com/eh/home.nsf/#pro ... romechanic
http://www.vegacontrols.co.uk/vegavib_v ... _index.asp
http://www.hycontrol.com/level_measurem ... rating.php


----------



## Mcluma (8 Nov 2012)

This looks promising

I checked a view and some are adaptable to what I’m looking for.

The blocks of salt are slowly going down (they dissolve from the bottom) -there are two next to each other, but both go down equally, so I only have to measure one

The measuring device has to sit on the top of the lit (the lit you take off to put new blocks in)

Manufactures do not provide a solution


----------



## Mcluma (8 Nov 2012)

Whiskywill.

You seem to be very well informed on this stuff

Do you know of a devise, very similar to a fluid measuring device, that instead of the float on the bottom, works inside of a tube, so when the level goes down it reach a sensor within the pipe, (simple on off)

The sensor pipe needs to have a reach of at least 400mm

Please see below for the drawing




Untitled by mcluma, on Flickr




Untitled by mcluma, on Flickr




Untitled by mcluma, on Flickr


----------



## Dibs-h (8 Nov 2012)

Chris

Quite simple to rig something up I suppose. It's a bit like the brake switch on most car brake pedals, but in reverse. Plastic rod inside a plastic tube with either a spring at the bottom (s\s as there's salt about) or a bit of a weight at the top. A low voltage circuit (warning lamp) that when the rod gets to a certain level in the tube - 2 contacts engage and the light comes on.

The point of the spring or weight is to ensure the "natural" position of the rod is downwards.

HIH

Dibs


----------



## Mcluma (8 Nov 2012)

I know, its so simple, i have already bult it in my head, but was hoping that i could just pull something off the shelf


----------



## Dibs-h (8 Nov 2012)

Mcluma":3j8fw0fa said:


> I know, its so simple, i have already bult it in my head, but was hoping that i could just pull something off the shelf



I suppose 'cos it's so simple - no one makes it nor sells it! :lol: 

Dibs


----------



## whiskywill (8 Nov 2012)

Mcluma":jmpjvxa2 said:


> Whiskywill.
> 
> You seem to be very well informed on this stuff



It's my job. If you've ever drunk Guinness, Bass, Tennants Lager, San Miguel, Coca Cola, Pepsi Cola or Babycham, eaten Demerara Sugar, used Kodak camera film, driven a Vauxhall or a Ford car or watched a Sony or a Panasonic television, chances are that one of our water treatment plants has had something to do with it. http://www.aweltd.co.uk/

I don't know of anthing exactly as you describe but a Kasuga float switch would do it. http://www.anadexlabs.com.au/shop/catal ... 16231.html Cut off one of the floats and measure the length of string so that it tightens when it reaches the level that you want. Sit the float on top of the salt when it is full and use the normally open contacts and wire a light, a bell or a buzzer in series and you will be warned when the salt needs refilling.

Alernatively, you could make something like you describe by having a rod inside a tube. Stick a magnet to the rod and stick a reed switch (plenty on eBay) to the outside of the tube at the appropriate place and you have a simple level switch. Beware of the maximum voltage/current that the switch can take. It is usually a low direct current.


----------



## whiskywill (9 Nov 2012)

Here a couple of options. The cat and mouse version uses a couple of pulleys but usually only gives a visual indication of the level but couild have a magnet and reed switch added. The weight of the piece on top of the salt needs to be more than the piece outside the tank.


----------



## Mcluma (12 Nov 2012)

I have been looking into it a lot more and I’m thinking of a non mechanical solution (the less moving parts the better)

So I was thinking of getting a reed switch located on the outside of the box (about 50mm from the bottom) and place a square 10mm thick block on top of the salt block with a strong magnet is positioned. At the edge of the block – facing the reed switch

Therefore when the block of salt dissolved (what happens on the bottom, therefore the block slowly “melts” away) the square block will go down until it reach a point which matches up with the reed switch that is positioned on the outside of the box. This in turn will then set off the alarm.

Question, I have read that the maximum opening (distance between reed switch and magnet) of the reed switches is around 8mm will this still work with about 3mm of plastic in between?

I was thinking of this 2 channel reed switch (there are two blocks of salt in the water softener


----------



## Racers (12 Nov 2012)

Hi,

Plastic won't affect the magnetic field, you could use a stronger magnet if you have problems.

Pete


----------



## Mcluma (12 Nov 2012)

Its good to know that plastic will not have much of an effect on the workings of a reed switch

What is better to use

The switch as shown above or an equal one but then with a relay built in, so it can be used to switch heavier volt devices


----------



## Dibs-h (12 Nov 2012)

Mcluma":t562gew5 said:


> Its good to know that plastic will not have much of an effect on the workings of a reed switch
> 
> What is better to use
> 
> The switch as shown above or an equal one but then with a relay built in, so it can be used to switch heavier volt devices



Or just get a pair of door alarm contacts - wire them in parallel, small 9V battery and a bright LED\buzzer. I wouldn't be inclined to switch heaver devices - unless there is a particular need to have a Klaxon go off! :lol: 

Dibs


----------

