The mystery of the green water in Washington’s famous pool

Washington’s large pool near the Lincoln Memorial turned an unexpected shade of green shortly after a recent update. The project cost millions and aimed to fix leaks and improve the water’s look. Workers repainted the bottom blue and added treatments, but green spots soon appeared. Experts say three key things help algae grow fast: nutrients like nitrogen and phosphorus, sunlight, and warm water. Warm water speeds up growth, and shallow pools let light reach the bottom easily. The dark blue paint might have made the problem worse by heating the water faster. Some businesses got paid a lot to resurface the pool and improve water quality. One company received nearly $15 million for resurfacing, while another earned over $1. 7 million to treat the water. Despite these efforts, algae blooms keep coming back. Experts note that simple fixes like hydrogen peroxide only kill algae temporarily. When algae die, they release nutrients back into the water, feeding new growth. The pool will need better long-term solutions, such as stronger filters or special treatments.This isn’t the first time algae has turned pools green. Records show similar problems since the 1920s. The government has tried many fixes over the years. Some leaders chose cheaper repairs, while others pushed for major upgrades. Costs for full replacements run much higher, but quick fixes often cause bigger headaches. The latest change included sandblasting and repainting instead of replacing older parts. Leaders have pointed fingers at various causes, including vandalism. The pool’s repeated issues have become a talking point in political debates. Some say the fast, low-cost method was a mistake. Others argue careful planning could have prevented the mess. Until better solutions arrive, the iconic pool may stay under watch.