I just think the novelty of these type of displays was up in the 90s, It’s time for an upgrayedd. I propose leprechauns flying up and down the river wearing water jet packs, shooting people with their Chicago-style hot dog cannons would be more with the times. What’s your idea?
3.52 x 10^(20) gallons according to the US national parks service.
The first Amazon result says a gallon works for 12000 (1.2 x10^4). So 3 x 10^(16). But that might be just for “detectable”, so more to be obviously green.