Dishwasher Materials

[Gardian]

Just a bit of a cautionary tale really.

Since 'finding' Leader Price a few years ago, we've been using their own brand dishwasher tablets.  Gradually, and it was a very gradual process, a film of cloudy clag accumulated on the inside of the m/c and on plates, glasses and cutlery.  To be honest, I put it down to a combination of the high chalk levels around here + the m/c probably getting on a bit. I tried cleaning the m/c (incl the jets), but to no avail.

Then, one day we saw an ad on TV for either Sun or Finish (can't remember which) talking about the cleaner for dishwashers. Thought it was worth a try and voila!

Immediately clean m/c inside, now use the branded tabs and all the crud is gradually disappearing from plates etc.  I know that this may be blindingly obvious to some, but it wasn't to us and we nearly bought a new m/c unnecessarily.

BTW, nothing against Leader Price as such: some of their products are fine, but this was one situation where thrift didn't pay.   

[FairyNuff]

I've had the same problem with Sun basic dishwasher powder. I assumed it was because I didn't have the salt dosage right and changed that, but the it's just as bad. I'll be buying some branded tablets before the cheap stuff is finished, which as a good Yorkshire lass I don't normally do.

FairyNuff

[cooperlola]

One thing you should watch, is not to add salt and rinse aid to their respective resevoires if you use "multi function" tablets (ie those which contain these things already) or you can seriously damage stuff like glassware etc by over-dosing.  In areas with high levels of "calc" in the water you can add some salt but don't over-do it or your glasses in particular will get misty and marked quite quickly.  This was explained to me my a guy who fixes these things for a living, as well as a dishwasher manufacturer (NEF) whom I got a bit narked with when their brnd new dishwasher mucked up all my nice glasses.  It did make a real difference.

[valB]

Every time we go to UK I bring dishwasher tablets back with me as I have also found glasses having a film on them. I even bought the more expensive tablets here with a brand name but still not very good. Also, I find that it is only English washing powder that gets my whites to how I want them and I have tried all makes here even well known barnd names to no avail.

[suein56]

[quote user="valB"]Every time we go to UK I bring dishwasher tablets back with me as I have also found glasses having a film on them. [/quote]

Not being one who returns to the UK I used to use the Lidl own brand all-in-one dishwasher tablets (W5 - shiny blue packet) with excellent results; but then, in a fit of remorse at not being 'green' enough started using the Lidl W5 Vert tablets and have found that they are brilliant all rounders. And I have less of a guilty conscience.

Sue

[Clarkkent]

[quote user="cooperlola"]One thing you should watch, is not to add salt and rinse aid to their respective resevoires if you use "multi function" tablets (ie those which contain these things already) or you can seriously damage stuff like glassware etc by over-dosing.  In areas with high levels of "calc" in the water you can add some salt but don't over-do it or your glasses in particular will get misty and marked quite quickly.  This was explained to me my a guy who fixes these things for a living, as well as a dishwasher manufacturer (NEF) whom I got a bit narked with when their brnd new dishwasher mucked up all my nice glasses.  It did make a real difference.[/quote]

I'm not disputing what you say (well, not really) but I thought that you do not add salt the washing water as such but into a reservoir which serves a water softener (eg Permutit type device). This is an ion exchanger which removes calcium from the water and makes it "soft". If you taste the water in a dishwasher it will not taste salty but bland.

I imagine that the "multifunction" tablets contain something like Calgon. If you add Calgon to soft water it should not produce a residue.

Perhaps someone who has a better knowledge of chemistry than I do can come to the rescue.

[andyh4]

Your understanding of the ion exchange resin is quite correct.  In machine water softeners are almost always phosphate based and these could etch glass.

 

The out of machine salt is only used in a back wash process and the salt itself should never enter the machine.  Salt does not etch glass.

[Bluebell]

I'm a bit confused (it doesn't take much!). I took over a dishwasher with the house this year, the first time I have used one. I put salt in the little resevoir with the screw top on the floor of the machine  and I use a Finish tablet which I just chuck in to lie at the bottom. A couple of times I've used the little bottle of cleaner which you hang upsidedown in the machine while you run it empty.

The water here is very hard. Am I right to put in the salt if I'm using the all-in-one tablet? Some of my cheap glasses are getting a bit murky.

[ColinE]

Hi

We are still in the UK, we had a simular problem. all the glasses were coming out milky, hought the machime had had it, read the instruction manual, it said about filling the salt container

Which I did, problem solved, when we did have a problem with the machine, a sevice guy from the manufacture told my misses to just use the cheap tablet, that they were good enough.

 

Regards  Colin

[andyh4]

[quote user="Bluebell"]

The water here is very hard. Am I right to put in the salt if I'm using the all-in-one tablet? Some of my cheap glasses are getting a bit murky.

[/quote]

 

Yes you are right to use salt.  If you look there is probably a control somewhere inside the machine that controls the amout of salt used - often a little plastic knob.  Turn it up a little and see if that imporves the glasses.

[cooperlola]

[quote user="andyh4"][quote user="Bluebell"]

The water here is very hard. Am I right to put in the salt if I'm using the all-in-one tablet? Some of my cheap glasses are getting a bit murky.

[/quote]

 

Yes you are right to use salt.  If you look there is probably a control somewhere inside the machine that controls the amout of salt used - often a little plastic knob.  Turn it up a little and see if that imporves the glasses.

[/quote]As said above, a guy I know who mends dishwashers, and the person on the help line at NEFF, both told me that I should not use both, as an excess of salt can etch into the glass, causing it to go cloudy - this is not a salt deposit, but a "scratching" effect which is irreversible.  Since then I have only used the all in ones and no additional salt (in spite of the water being very hard here) and  I have never had the problem again.  Nor have I had any problems with my dishwasher.

[Clarkkent]

The following is taken from Wikipedia. Perhaps it will help.

Dishwasher salt

In some countries, especially in Europe, dishwashers include a built-in water softener. Dishwasher salt is used to recharge the built-in ion-exchange water softener. Unlike salt used for culinary purposes, it does not have added iodide salts. However, it should have minimal iron and manganese salt content, as these mineral ions tend to form precipitates that clog the ion-exchange resin.

Some dishwasher detergents are marketed as not requiring the use of dishwasher salt. These instead use increased levels of phosphates to increase the solubility of hard water ions. In very hard water areas, the amount of phosphate may be insufficient, requiring the additional use of salt in any case.[3] Some newer dishwashers have a setting for "all in one" tablets. Incorrect use of "all in one" tablets may not be covered under the warranty; it is advisable to check the instruction book when using these types of tablets.[4]

Pouring table salt, detergent (or anything other than dishwasher salt) into the salt compartment will damage the water softener unit. However, it is possible to use salt granules or tablets sold for whole house softening units and save a significant amount of money in the process. Softener salt in 25 kg bags will work out about one third of the cost and is easily available.

[edit] Hazing of glassware, prohibition on dishwashing lead crystal

Glassware washed by dishwashing machines can develop a white haze on the surface over time. This may be caused by any or all of the below processes, only one of which is reversible:

[edit] Limescale deposit

If the dishwasher has run out of the salt that recharges the ion exchange resin that softens the water, and the water supply is "hard", limescale deposits can appear on all items, but are especially visible on glassware. It can be removed by cleaning with vinegar or lemon juice, or a proprietary limescale removal agent. The dishwasher should either be recharged with salt, adjusted appropriately for the hardness of the supply water—or possibly this is a symptom of failure of the ion exchange resin in the water softener (which is one of the more expensive components). The resin may have stopped working because it has been poisoned by iron or manganese salts in the supply water.

[edit] Silicate filming/etching/accelerated crack corrosion

This film starts as an iridescence or "oil-film" effect on glassware, and progresses into a "milky" or "cloudy" appearance (which is not a deposit) that cannot be polished off or removed like limescale. It is formed because the detergent is strongly alkaline (basic) and glass dissolves slowly in alkaline aqueous solution. It becomes more soluble in the presence of silicates in the water (added as anti-metal-corrosion agents in the dishwasher detergent). In certain cases, the etching will primarily be seen in areas that have microscopic surface cracks as a result of the items' manufacturing.[5] Limitation of this undesirable reaction is possible by controlling water hardness, detergent load and temperature (see Maytag Web site, Troubleshooting on Filling the standard tub detergent dispenser). The type of glass is an important factor in determining if this effect is a problem. In hard-water areas more detergent is needed to help prevent etching, and some dishwashers can reduce this etching effect by automatically dispensing the correct amount of detergent throughout the wash cycle based on the level of water hardness programmed.

[Bluebell]

Thanks, Clarkkent. I think my machine must be quite old as the instructions do not mention the all-in-one tablets. But that article was a great help.