The most common cause of a goiter is lack of iodine, ...Even with the right amount of iodine, the thyroid gland can swell, creating a goiter. This can occur in any type of thyroid disease, including hyperthyroidism, hypothyroidism, thyroiditis, and thyroid cancer.
Shock treatment powder bags. Skim off whatever algae you can from the pool using a pool skimmer. Scrub the inside edges and walls of the pool with an algae brush to dislodge stuck algae. Purchase sufficient amounts of algaecide, as noted in the instructions on the bag, that match the total gallons of water in the pool.
Shock the pool and then thoroughly vacuum your pool. Based on the water sample, you'll likely have to add some chemicals and let the pump run for a few hours. Once this is done, you'll added the dealer recommended amount of algaecide and winter shock. Once added, I put the pillow in place and put the winter cover on. 3. Drain the water below the skimmer. You can do this by backwashing the filter. Be careful not to run the pump dry.   4. Cover the skimmer opening with the cover provided with the closure kit, and remove the eyeball on the return.   5. Remove the hoses. Insert a black rubber stopper in the return opening.