Are you using an effective water filter system or are you using your body as a filter?
I recommend to all my clients to use a water filter. If you already have a water filter does it remove fluouride? As someone who has Hashimotos (autoimmune underactive thyroid condition) it is very important to filter fluoride and other chemicals as it contributes to further reduced thyroid function.
I use & recommend Waters Co. water filters ranging from simple water bottle to jug to bench top system as they filters 99.9% of nasties from the water while also alkalizing it at the same time.
I have the benchtop BIO 1000 10 Litre filter system at home. It gives a lovely clean, pure taste. It alkalizes, removes up to 99.9% contaminants and remineralizes ordinary tap water for great tasting healthy water.