It's just that, raising lotus or water lily in a "medium," without the cooling effect of a pond, wouldn't be quite so "cool." As a bird-watcher once said, seeing a bird without its natural surroundings is "like a huge apple but without the sweetness, and therefore of no interest at all."
只是，把睡蓮、荷花種在「介質」裡，少了消暑的水池，不正如賞鳥人說的「生活中缺乏草澤、泥沼的湖泊，就像失去了甜味的大蘋果，不再生趣盎然」？