I can answer this because it happened to me. I had a 30 gallon aquarium which I was planning to convert into a palludarium so I was letting the fish just live out their lives. I was down to two goldfish. The filter went out. I was hoping that the goldfish would be big enough by the time the weather became warm enough to add to the small goldfish pond in the backyard. What surprised me were the plants! They took off in a big way. The two fish did fine for a long time although I did lose one at about the six month mark. (I honestly can't say the conditions of the tank is what killed this fish. I buy the 30 cent feeder goldfish from the pet store that are bred for food, not longevity. Many of them don't live long under the best of conditions.) The other lived fine for over a year until I could move her (him?) to the pond. The tank seemed healthy and never smelled bad as you might expect from uncirculated water. Based on my experience, if you want to try this I recommend:
a very large tank
only 1 very hardy fish
LOTS of plants
no expectations of aesthetics as the tank will be overrun with green
I work at a children's science center and I briefly considered recreating this as an ecological exhibit but decided against it as I don't think it would support enough diversity to make a good example.
The aquarium is now a very healthy palludarium with both aquatic and terrestrial plants, a few fish and fiddler crabs. Oh, and a in-tank filter that doubles as a beautiful waterfall feature.
a very large tank
only 1 very hardy fish
LOTS of plants
no expectations of aesthetics as the tank will be overrun with green
I work at a children's science center and I briefly considered recreating this as an ecological exhibit but decided against it as I don't think it would support enough diversity to make a good example.
The aquarium is now a very healthy palludarium with both aquatic and terrestrial plants, a few fish and fiddler crabs. Oh, and a in-tank filter that doubles as a beautiful waterfall feature.