Fluoride can be bad for you, just at much higher doses than they put in water supply. It can cause issues with bones and neurological development. Again, only in very high doses over a long time. It happens a lot in poorer countries where they can’t treat well water.

https://en.m.wikipedia.org/wiki/Skeletal_fluorosis

Potatoes form underground but they can also flower and make fruit. The fruit looks like a little tomato. My advice is to not eat the fruit; it is toxic.

Also, it needs a way bigger pot to make more potatoes.