Whether you have neurotoxicity, fluorosis (teeth stains from excessive fluoride), or you want to avoid these things, you can eliminate fluoride from your life (with difficulty). In case you do not have the means to rid your world of fluoride, unfortunately you cannot filter it out of your water.
According to ThoughtCo, you can use reverse osmosis, activated alumina, and distillation to filter your water of fluoride. In that case, it may be easier to purchase bottled water (I know it’s bad for the environment), move, or detox. Here’s how to do the last thing.
Lucky for you, the Earth can do some pretty cool things and fluoride binds with a few other elements found on the planet.
For a regular detox, you can always use a dry infrared sauna every few days or once a week (as much as you can afford – someday I will buy my own, I swear). You can also eat foods high in antioxidants or that stimulate glutathione production. Some of these include colorful berries such as blackberries, cranberries, blueberries, and (with the highest concentration) goji berries. If you eat goji berries, don’t eat too much since they contain very high levels of Vitamin A – yes, you can overdose on too much Vitamin A. Cilantro is a good antioxidant and shilajit, a Himalayan black tar/rock substance, is supposedly very good for detoxification.
For fluoride specifically, tamarind, selenium (high contents found in brazil nuts), magnesium, and iodine (get it from seaweed) are all known to bind with fluoride and get that nasty stuff out of your system.
Check out my master list of non-fluoridated bottled water.