Water softener maintenance

[M1957]

Our softener has brown sludge in the water which can be seen when the salt bin is empty. Is this normal? Presumably it's from impurities in the salt.

It's probably at least 20 years old and I'm not sure how effective it is and if any maintenance is required.

Any advice would be appreciated.

 

[JohnD]

you can sponge it clean next time the salt runs out.

Proper softener salt, in pebbles or tablets, is very pure, but I've known dirt and dust fall off sacks of salt that have been stacked in a shed or carport.

Are you sure nobody ever used rocksalt?