in briefTrump has long sought to "make America beautiful again," but his latest efforts have been undermined by biology. The botched renovation of the Lincoln Memorial Reflecting Pool have become the latest flashpoint in a polarised United States.Strips of "American-flag blue" paint are rising from the bottom of the Lincoln Memorial Reflecting Pool, videos circulating online appear to show, in the latest disaster to hit its botched $14.6 million ($20.8M) refurbishment.The Reflecting Pool, which civil rights activist Martin Luther King Jr. looked over as he gave his famous "I have a dream" speech, has undergone a makeover at the direction of Donald Trump to commemorate the country's 250th birthday on 4 July this year.In May, the pool was drained and a commercial-grade sealant was reportedly added to its granite bottom. Donald Trump is facing federal legal challenges over his moves to renovate some of Washington's historic landmarks. Source: Getty / BloombergThe Virginia-based Atlantic Industrial Coatings company was awarded a controversial US$13.1 million ($18.7M) no-bid contract for the job after having previously worked on one of Trump's golf courses.News that makes senseYour trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox."We did a hell of a job," Trump told reporters at the White House last week upon completion, claiming just US$10 million had been spent. Company owner Eddie Wood confirmed in an email to US publication NBC that the cost had, in fact, blown out."But everybody’s looking at that Reflecting Pool," Trump continued. "They can’t believe it reflects. We used a dark blue, it’s called American flag blue."However, visitors to the iconic Washington site have noticed that the water has turned a distinct shade of green. Wayne Sobey, environmental consultant at Algae Control Australia, told SBS News that "shallow, flat, non‑circulating pools" like the Lincoln Memorial's create "almost perfect conditions for algal growth," something the administration is continuing to deny is a problem.Here's how the colour of the Lincoln Reflecting Pool became the latest political flashpoint in a politically charged United States. A timeline of reflectionTrump's desired overhaul of the Reflecting Pool is part of an ongoing administration push to "beautify" American cities, and its capital in particular, following what it sees as years of Democrat neglect. Such projects in Washington DC include the complete knock-down and rebuild of the East Wing of the White House, the plans to build a towering victory arch in Washington that will exceed the Arc de Triomphe in Paris, and a US$7.5 million plan to paint the Eisenhower building.The Lincoln Memorial Reflecting Pool is a 619 by 51 metre rectangular pool built in 1922 between the Washington Monument and the Lincoln Memorial. While it draws millions of tourists each year, it has long had issues with water clarity. It's 6.75 million gallons of still water see blooms of the photosynthetic organism each summer, something Barack Obama spent US$34 million to fix — unsuccessfully. "Healthy water naturally contains algae," Sobey explained. "The issue isn’t their presence — it’s when conditions shift so far in their favour that they dominate the system."In March, after previously expressing a desire to renovate the pool, Trump announced that himself and secretary of the interior Doug Burgum were turning their attention to it. He promised that Americans would "end up with a beautiful, beautiful reflecting pool, the way it’s supposed to be.""Much better than it ever was, actually."Trump made his renovations to the Lincoln Memorial Reflecting Pool a key part of preparation efforts ahead of the US' 250th anniversary. Source: Getty / Kevin DietschIn talking through his plans, Trump touted his expertise at building "more than 100 swimming pools" and noted "I have a guy" when discussing contractors for the work. However, he faced criticism for speeding past planning processes meant to preserve Washington's heritage, something his administration dismissed as partisan sniping while praising the real estate developer's design acumen.In May, Trump posted an artificially generated image of himself and members of his cabinet floating in a deep blue reflecting pool. Days later, he was seen driving across the drained pool as contractors sprayed deep-blue paint over its base. There is disagreement over whether the Reflecting Pool has been painted or sealed. Source: Getty / Al DragoWhen questioned why he was focusing on the pool and not the ongoing war with Iran, Trump lashed out at a reporter, saying that "truckloads of garbage" had been removed from it. "Our country is about beauty, cleanliness, safety, great people. Not a filthy capital," Trump said."We're fixing up the reflecting pond to the Lincoln Memorial, the Washington Monument and you say, 'Why are you fixing it up?'" he continued. "Because you can understand dirt maybe better than I can, but I don't allow it."A growing problemIn June, Trump announced the pool had opened "to rave reviews," arguing its surface had not been painted but sealed with a "highly sophisticated material, industrial strength, that could last for 100 years, applied by very talented people".Within days of the opening, videos began circulating on social media showing algae returning to the water, with online commentators attacking it as a failure of the administration. Supporters of Trump downplayed or rejected the reports.Soon, maintenance teams were seen dumping bottles of hydrogen peroxide into the pool to combat its growth. On Thursday, the US department of the interior stated that the Reflecting Pool water was now "crystal clear, and our National Park Service team is now vacuuming up the dead algae resting on the bottom".The department described using "advanced nanobubbler technology" as a permanent solution to algal growth that has "plagued every Lincoln Reflecting Pool reopening — most infamously Obama's reopening — since 1922.However, on Friday, further videos began circulating of more algae in the pool. Worse, sections of the paint appeared to be flaking off in large chunks. "That American flag blue paint, it's peeling away. The $14 million job to redo the bottom of this reflecting pool is falling apart before our eyes," Jonathan Karl of the US ABC News reported on Friday from the pool. "The algae is still here, but the paint appears to be going away."SBS News has contacted the US department of the interior for comment.A difficult fixUS media have decamped to the Reflecting Pool while protestors dressed in green have been seen chanting "let's go algae.""I want my money back after seeing this. I think our resources could be used a lot better elsewhere," Robert Dale of Edwards, Colorado, told the Reuters news agency on Friday. "I think this reflecting pool was beautiful before, before all this attention."Sobey said that, while the issues with the pool are to be expected, they are not insurmountable, although they will require significant further investment to fix.Algae is a normal part of a healthy water system, but can outcompete rival species if the conditions are right. Source: Getty / Chip SomodevillaHe argues that the "bright, reflective liner" used in the pool may have increased light in the water. "Algae respond aggressively to increased light, especially opportunistic species like green algae and certain cyanobacteria," he said. In addition, draining and refilling the pool essentially resets its "microbial community," leaving it prime for algal dominance."You remove the established biofilm and replace it with nutrient‑rich, biologically 'empty' water," he said. "That creates a classic rebound scenario — fast‑growing algae colonise first, long before the slower, stabilising organisms return."While hydrogen peroxide is commonly used in water treatment — breaking down into harmless water and oxgyen — it is only a temporary measure against algae as it doesn't address the underlying factors contributing to its growth. "When algae die suddenly, they release nutrients back into the water. In stagnant systems, this can actually fuel the next bloom, creating a cycle of crash–regrow–crash.In addition, hydrogen peroxide will also kill both good and bad bacteria. "That prevents the waterbody from developing a stable microbial ecosystem, and the very organisms that would naturally suppress algae are eliminated before they can take hold.While algae cannot be removed entirely, it can be controlled. In a body of still water like the Reflecting Pool, that will require circulation, aeration, and biological stabilisation. The National Park Service’s effort to install a microbubble system is "a step in the right direction," Sobrey said, as the technology shifts the water chemistry "away from conditions algae prefer." However, algae control requires long-term strategising and cannot be solved immediately. "Once the microbial community stabilises, the pool will naturally return to the clear appearance people expect," Sobrey said."But if they continue down a purely chemical route, they’re essentially treating it like a swimming pool — clarity maintained only by constant chemical loading, rather than by a healthy, self‑regulating waterbody."— With additional reporting from Reuters.For the latest from SBS News, download our app and subscribe to our newsletter.