What are these cloudy spots on dishwasher interior?

Postik

Dishwasher is 5 years old, I've lived here for a year.  These cloudy spots started to appear around 6 months ago on the stainless steel interior.  They are completely smooth, and cannot be removed (have tried vinegar and Barkeeper's Friend).

Around 6 months ago I re-filled the dishwasher salt (the light came on indicating to do so).  The spots have probably started to appear since then, but not immediately afterwards.

I am using Tesco 3-in-1 dishwasher tablets.  The dishwasher manual has conflicting information about whether or not to use salt when using 3-in-1 tablets and since we're in a hard water area the general consensus is to still use salt.

Oddly enough the spots are only appearing on the dishwasher floor and not the walls, ceilings or cutlery.

Is this related to the tablets, the salt or something else?

Rodders53

It is most probably caused by your filling of the salt reservoir and spilling the granules on / around the dishwasher base and not ensuring every last speck was removed.  After all it gets dissolved in the water, doesn't it.

The salt, apparently, can cause cosmetic 'pitting' on the SS surface.  Allegedly even on SS saucepans if coarse salt flakes are added too early and they sit for a time on the bottom of a pan of water and veg without fully dissolving.

It is just a cosmetic issue.

Albermarle

I am using Tesco 3-in-1 dishwasher tablets.  The dishwasher manual has conflicting information about whether or not to use salt when using 3-in-1 tablets and since we're in a hard water area the general consensus is to still use salt

If you are adding salt anyway, you can buy dishwasher tablets that are not 3 in 1 . They are cheaper and  work fine, but they are not heavily promoted or available in all supermarkets.

Postik

Rodders53 said:

It is most probably caused by your filling of the salt reservoir and spilling the granules on / around the dishwasher base and not ensuring every last speck was removed.  After all it gets dissolved in the water, doesn't it.

The salt, apparently, can cause cosmetic 'pitting' on the SS surface.  Allegedly even on SS saucepans if coarse salt flakes are added too early and they sit for a time on the bottom of a pan of water and veg without fully dissolving.

It is just a cosmetic issue.

I'm not sure it's from spilling the salt because I made sure I didn't spill a single grain (I used a funnel), then I ran the machine on empty afterwards.  The spots keep appearing every few weeks and I filled up the salt months ago so I think any stray grains would be long gone by now.  Like you say it's probably cosmetic, it just annoys me when a new one appears!

Albermarle said:

If you are adding salt anyway, you can buy dishwasher tablets that are not 3 in 1 . They are cheaper and  work fine, but they are not heavily promoted or available in all supermarkets.

Yeah that might be worth looking at.  I have found the Tesco tablets to work fine though on the dishes themselves, not had any issues with cloudy glasses or rusting cutlery.