Im not sure if this has been posted before, I dont think it has.
But check out this huge aquascape! It's like a lake almost! I found this on Aquatic Plant Enthusiasts (APE)
"2 million litres of water are filtered at the rate of 1.2 million litres per hour, and CO2 injection system provides the plants with the ideal conditions to thrive, prevent algae and maintain stable pH levels. Its unreal. "