I have a MOther-in-laws Tongue in a terra cotta planter with a drainage dish and it keeps getting covered with a crusty white substance. I have simply wiped it off, used soap and water, and even lysol wipes and it keeps coming back. WHat is this stuff and how do I get rid of it!! HELP

the crusty white is the minerals in the water you are using to water your plant. it is a "normal" aging of the terra cotta planter.

But it is a new pot, I've only had a plant in it for about a month, and it's thick and falling off in clumps like shingles or something. That's normal? The water here in Germany really is full of minerals, you can smell them. Can I use something to "defuse" them a bit without killing my plant?

You can try using rain, or distilled water, or just cut back on tap watering all together. Snakes can go for few weeks or more without water and food, especially in the winter months.
Being that the leaves are semi succulent, they can hold water longer than of the many of the other thinner leaved plants.
Let the soil dry out well between waterings and it's not over-potted and you shouldn't get as much of the white mineral stuff.
I'm watering mine about once a month or so.

Tammy I have some in terracotta I spray them with distilled water in between waterings if you let it get overcrowded in the pot it will bloom. DO NOT over water I never water mine more then once a month in summer and we get pretty warm here in summer 100 to 115 + heat index gets real humid also in winter I spray with a spray bottle and very seldom water when I do I will use some water from a bird cage that is plenty and sometimes it has a little natural fertilizer in it too.

Washing the outside of terra cotta pots with vinegar usually removes mineral stains.

someone asked about this before...i forget who made the suggestion...use denture cleaner (efferdescent tablets) to clean the mineral build up off.

to hide it, put the clay pot inside a larger decorative pot - you can top it off with some moss to hide the fact that you've doubled up the pots.

Perhaps use a ph tester / strip to see what the PH is and add an acidic substance to compensate the alkaline problem… maybe tea...flush pot with plenty of water to remove any build up on the surface of the soil...