If I ever have a pond with fish again I want to try it. It would probably drive my cats crazy though LOL (Use a heavy glass vase and invert it on some concrete blocks so they can swim in from the bottom. Submerge the vase and turn it up under water so the vacuum created keeps the water inside. Make sure you have a heavy glass container or the weight of the water will shatter it.)
22 Small Garden or Backyard Aquarium Ideas Will Blow Your Mind
After scouring antique and junk stores we settled for this unique garden pond. We used a pump system purchased from a local garden center, filled it with water and a few dime store gold fish, and have enjoyed it for many years. The fish are shared with a local school, where they winter indoors and then return in the summer for an outdoor vacation.