Fish are like plants that move.
When you make a lovely garden, you most enjoy the lovely dancing of the colorful flowers in the breeze. NO. SHUT UP. THAT'S WHAT YOU ENJOY MOST AND YOU'RE NOT SAYING OTHERWISE. So what you need is a little garden fish tank that will basically just be a never-ending dance of plants, except instead of plants it'll be fish. LOOK IT MAKES SENSE IN OUR HEADS OKAY?