The algae-infested water in the refilled Lincoln Memorial Reflecting Pool is even more disgusting than its green color suggests. During an episode of The Issue Is, CNN’s Washington correspondent Sunlen Serfaty took a sample from the pool that President Donald Trump ordered be repainted and refilled as part of the America250 celebrations and sent it off for testing.

While the Lincoln Memorial’s pool takes on a punchy new shade, the country’s wealthiest homeowners are increasingly choosing gray to make their pools disappear.

It's had issues with algae for decades.