purple stains on white ceramics

[admin]

Hi there. We have had purple streak stains on our white ceramics. The drying cycle is implied, as they look like rivulet generated. They can’t be removed! We have tried changing detergent, and finish. We have varied salt & finish dosing. One suspect is the separate house watersoftener. This was added circa 10 years ago, but I don’t recall this problem starting more than c5 years ago. We are supplied by South West Water, and have purple algae in the main shower. Finally we exchanged the dishwasher for a Miel to no improvement (really quiet though). Any ideas?

[kwatt]

Re: purple stains on white ceramics

It is certainly something to do with the mains water. There’s no chance that two machines have the same issue and the purple in the shower is the dead giveaway.

I’d have a plumber look into it for you.

K.

[Martin]

Re: purple stains on white ceramics

humph,

Firstly if your water softener is supplying the dishwasher with softened water, then no need to add salt in the machine as well. Avoid liquid detergent and stick to powder or better still tablets.

Many makes of dishwashers will run happily on a hot water supply provided it does’nt exceed 65 degrees Celsius. I’m not sure if Miele machines have such compatibilty, but you might like to check that possibilty out and switched to hot fill. Hot water systems kill most algae anyway so that may be your best option. If you get the same results in the shower of the algae, chances are it’s coming from the cold water.

I would personally rule out your water softener as the source but do contact South West Water and ask if they could ‘test’ one of the damaged ceramics in their lab for you 💡

Other than that, I’m stumped on this one 😕

Martin

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