But it does involve a Peace Lily.

Freshwater Aquariums ***
Q & A - Betta in a Vase
Why Bettas Should Not be Kept in a Vase

Q: I've been reading about the craze of keeping a Peace Lily and a Betta
splendens in a vase together. What do you think - is it safe for the fish? A:
The argument made for keeping fish in a vase is that pumps, filters, and other
aquarium equipment, do not exist in nature. By putting the fish in what appears
to be a natural environment the assumption is made that it is inherently as
healthy as, if not healthier than, an aquarium. That simply isn't the case. It
is true that in nature the Betta lives in shallow rice paddies and swamps.
However those waters represent a complete ecological system, which cannot be
replicated in a small vase. Rice paddies are shallow but are still part of a
much larger body of water that serves to dilute toxins. Scavengers and bacteria
present in native waters break down wastes and render them harmless to fish.

** In nature the Betta lives on a diet that consists predominantly of insects
and insect larvae. In fact, Bettas contribute significantly in controlling
mosquitoes that abound in their native habitat. The Betta's digestive tract is
geared for meat. Its upturned mouth is designed to grab insects that have
fallen into the water. Although they may be observed picking for morsels on
plants and rocks, they are not bottom feeders by nature. A diet consisting of
vegetable matter may keep them alive for a while, but it is not natural or
healthy. Over time they will slowly be starved of the proper nutrients, and
more easily fall victim to disease.

** Another factor that has been completely overlooked in the Lily-Betta
combination is the element of water temperature. The primary reason Bettas in
small bowls are often listless is because the water temperature is too low.
Bettas are native to countries such as Thailand where the climate is hot and
moist. The ideal water temperature for the Betta is about 80 degrees
Fahrenheit. Although they can survive at lower temperatures, they become
lethargic and may even refuse to eat. Unless you live in a very warm climate,
the water in a vase cannot be maintained in the upper 70's to lower 80's.
Subjecting the Betta to cool temperatures is the same as if you or I had to
live in a house where the temperature that didn't rise above 60 degrees.

** Lastly, there is the issue of how the betta breathes. Like other fish, the
Betta derives oxygen from the water. However, it also has special organ that
allows it to breathe air directly. Its upturned mouth allows it to easily gulp
air from the surface, and therefore survive in waters that are low in oxygen.
If the Lily vase is not properly set up, there will be insufficient open space
at the top of the water for the Betta to reach the air. As the oxygen dissolved
in the water is used up, the Betta will need to breathe air more often. Should
it have trouble reaching the surface, it may become deprived of the oxygen it
needs to survive.

** The Peace Lily-Betta combination is clearly a popular fad, but it is neither
natural nor healthy for the fish. A dog or cat owner would never consider
shutting their pet in a small closet with minimal heat, food, and air. The
Betta should not be treated any less humanely.