Sounds like you weren’t a competent brusher. Fact of the matter is you get more than your recommended daily intake of fluoride from toothpaste and mouthwash. Adding more via water doesn’t magically product “more protection”. There are far safer and more effective products we could use like NHA that actually reverse and prevent demineralization, rather than just preventing to a small degree as fluoride does. If you’re so concerned with fluoride being removed from your water, add it back at home