GarySlusser
That sounds like iron staining. Water with as little as .3 ppm or mg/l of Ferrous iron can cause staining from a yellow to dark rusty orangish reddish brown. It could also be IRB (iron reducing bacteria). That causes a clear to the same colored slime. Either will usually wipe off with little effort but somtimes the staining requires a product used to remove them such as Iron Out etc..
A water softener or iron filter removes Ferrous iron but IRB will prevent them for working so it’s important to identify what type iron you have in the water. Disposable cartridge type filters will not work for either type of iron; they only work for Ferric iron which is oxidized Ferrous iron and are called sediment filters.
Gary
Quality Water Associates
