National Park Service crews on Tuesday battled the algae bloom plaguing the newly refurbished Lincoln Memorial Reflecting Pool in Washington, D.C. 

Employees and contractors of the agency deployed hydrogen peroxide and ozone nanobubbles to clean the pool, the Associated Press reported. 

The hydrogen peroxide, which is used in spas and natural swimming pools, is milder than chlorine. The nanobubbles reduce the need for chemical treatments. 

The Trump administration awarded nearly $15 million in contracts to resurface the bottom of the pool with what President Trump called the "latest and greatest filament" and an "American flag blue" color. 

Algae has plagued the pool since its construction more than 100 years ago. The pool is larger than 10 Olympic-sized swimming pools, and the water comes from the often-putrid Tidal Basin.