It’s mostly lime and calcium build up. May also be some other type of minerals there-depends on your local water. It won’t hurt you, you’ve been drinking it all your life. Over time, it will eat away at your appliances. Cleaning it is simple-use CLR, Lime Away or similar product. Might want to check your shower head as well, bet you’ll find a little build-up there too. Your water filter is little more than an activated carbon filter. It will make the water taste and smell better but does nothing for removing minerals. Only two products can help in that arena, a water softener-which doesn’t actually remove the minerals but gives them sodium molecules to attache to as they pass through your appliance and RO reverse osmosis systems-which are pretty pricey for home use.

Mineral buildup. When it gets obvious – boil some cream of tartar
in water in it. And then wash with soap and water.

it is lime deposits and limeaway will disolve it but be sure to wash it when done with limeaway they also make a coffee pot cleaner that will disolve it…….i hate it the only way i think is to have a water softener…..to be totally rid of it…..i buy bottled water and i have resolved a lot of it…i just use for teas and coffee and to drink and we give it to our dog as she is spoiled and wants cold water from the cooler…

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It is mineral deposits.It won’t harm your body but it will shorten the life of your appliance. You can boil vinegar in it, and it will dissolve it. As frequently as you see a build up, usually once a month

Normally they are calcium deposits. If left on cared for they will develop such thick scale it will ruin your appliance. Get some CLR at the market it will usually clean the deposits quickly and leave you appliance looking like new.

~~~Your local town water supply probably has Hard water,,that will cause the calcium deposites. We have the same thing where I live. A water softener would help. We rinse our dishes and glasses with some vinegar water. Im not familiar with the Brita filter system. How often are you suppose to change filter?

It’s calcium- just scrub it out when it starts to build up.

It’s calcium. Filters don’t filter everything out, as they would have us believe. Use vinegar every couple of weeks, depending on how much calcium you get.

It is calcium deposits and you should clean it often