Dishwasher salt question

[Jon Parker]

Not striclty a DIY question I know but I hope you'll bear with me.

Recently and suddenly our dishwasher has started leaving us with cloudy glasses (rescued only by hand washing), a "powdery" feel on the porcelain and an almost irridescent smeary mess on the cutlery (which wipes off easily but that's not the point!).

We've not changed any of our chemicals but I did notice the salt doseage controller had been turned down to it's lowest setting (it should be medium).

Would lack of salt explain the results I am seeing?

Thanks Jon

[Nick]

Yes. Brine solution is used to cleanse the filter bed. No salt, no brine. Lack of squeaky clean stuff and feel good factor. I've used a permutit for about 30 years. Touch wood, it is still working well. How did the dosage controller come to be altered? Nick.

[gareth]

Also, you have to ensure that the type of salt is correct. It should be almost pure sodium chloride. Too high a concentration of calcium and / or potassium salts will prevent the back-flushing of the filter (which has ionised out the calcium) from working correctly.

Caution. I have not done chemistry since 'O' Level 47 years ago!

[Roger Mills]

Yes.

[Rick Hughes]

Never used any Salt in ours ... just a standard dishwaher tablet ... nothing else

[Davey]

Same here, and we are in an area officially classified as having "Very Hard" water. We use Fairy Platinum tablets, and have never had any problems.

[Andrew Gabriel]

Some tablets have a water softener for the final rinse.

Rinse-aid will also help, as it encourages the water to run off the items rather than to dry on them.

[Onetap]

Some dishwasher tablets ( 3-part, powerball, etc) contain some polyphosphate chemicals (forget what exactly) that dispense with the need for salt & softening. It's the same stuff used in Combimate devices.

The cheaper ( e.g. Aldi) tablets which don't have this and will produce the effect described if used without salt. Fine with salt.

Summary; it's limescale.

[gareth]

Actually you cannot dispense with the need for salt, because the salt circulation does not involve the washing cavity wherein the tablet resides; it being a separate circulation wherein brine is backflushed through the resin block and straight down the drain.

Even with tablets, youstill need salt.

And for those who say that they do not use salt even in a hard water area, you are shortening the life of the dishwasher.

[Andrew Gabriel]

Without the salt, the water softener doesn't get recharged, but if you don't need the water softener to operate, then you don't need the salt.

Some machines also use the flushed water as a condenser at the end of the drying cycle, but it doesn't matter what's dissolved in it.

You are missing the point that the water softening is built in to some of the tablets.

[Davey]

Please explain.

[Tim Streater]

And I'm curious to know whey my d/w needs salt, even though it's being fed post-softener water.

[Capitol]

[Graham.]

The supermarket distribution chains are flexible enough to provide ethnic products appropriate to the demographic need.

They fail however to be selective when stocking hard water products in soft water areas like here in Manchester.

[Onetap]

Aldi and Lidl tablets were the 'Which?' best buy, according to the Express.

Read what it says on the box.

The Aldi tablets I bought some months back required salt for the softener.

I didn't put salt in, having been using the Finish tablets; the glassware got cloudy.

I then put salt in, cloudiness stopped.

Go figure.

[Onetap]

With some tablets, you don't need salt. They've got that Calgon-type stuff in them.

You're a tad confused.

[dennis]

If you are using the inbuilt water softener you need salt. The tablets do not refresh the ion exchange resins in the softener, they can't as they never go near them.

If you don't refresh them you may make them unusable after a while.

AFAIK all calgen is is some phosphate, the stuff they used to put in washing powder before the greens decided it was bad for the environment. It softens some types of water and reduces the scale depositing on hot surfaces like elements.

It probably won't work well in a dishwasher as it has two, or more, hot cycles and you don't want anything left over in the final hot rinse.

BTW unless you make a habit of using hot washers in the dishwasher the water probably won't get hot enough to deposit scale.

[Jon Parker]

Thanks. Think I've identified the issue as a knackered gasket meaning very little pressure to the top spray arm.

No idea. Probably the wife accidentally.

Cheers all. Jon

[Mike Lane]

On Feb 23, 2014, Andrew Gabriel wrote (in article ):

I've always assumed the main reason for dishwashers softening the water is to prevent limescale building up on the water-heater.

[Onetap]

The resin will survive without being regenerated. The polyphosphate stuff (or whatever it is) prevents limescale being deposited.

I've heard that resin gets exhausted and needs replacing, but that was from softener companies that wanted to charge me an arm and leg to replace good resin.

I tested the softened water, with a Camlabs drop titration test kit, when the softener had passed the rated volume. It was still soft, so I told them to f*ck off, though not in so few words.

They were trying to pull a fast one, I knew it, they knew that I knew it.

I've run my softener for years without salt using the all-in-one type tablets.

I've recently started using the tablets that require salt. The softener still works, when I put salt in.

The last process (on my one, anyway) heats the dishes and evaporates any remaining water. That's why the limescale/cloudiness is so easily noticed.