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.
Remember, when you have a swimming pool algae problem, there is no quick fix. It will take time, effort, and patience to clear up your pool. When your swimming pool chlorine is down to 1.0ppm-3.0ppm the pool will be safe to swim in once again. At this point you can use a clarifier to help with the filtration.