These medications may also be used to treat thyroid cancer or other thyroid conditions. The long-term safety of levothyroxine is well established. Typically side effects only occur due to overdosage of the medication. For more specific information, consult with your doctor or pharmacist for guidance based on your specific condition and current medications.
My neighbor just puts 3-4 gal of bleach down the pipe, then waits 24 hrs. Then runs water through all the fixtures until the bleach smell is gone. He said it usually last for 1-1/2 years. Our water is relatively soft, but does have a bit of iron in it.
Interestingly, we bring water from the city where water is chlorinated. Ten minutes later when you open the container, there is a very distinct bleach or chlorine smell because the chlorine has left the water and is existing in a gaseous form in the small air space at the top of the container. Good question.