Demo
Save the Little Fish demo · Small, about 20 gal · calm, like a pond or swamp · running 1004 days · shared October 2026
A classic 20-gallon planted tank. Cool-tolerant fish, gentle filter, and shrimp cleaning up.
Paracheirodon innesi
Upper Amazon basin: Peru, Colombia, Brazil · blackwater stream
Photo: Holger Krisp, CC BY 3.0
× 12
A dozen is the minimum; they look far better in a bigger school.
Corydoras panda
Clear Andean foothill streams, Peru · stream
Photo: Chronotopian, CC BY-SA 3.0
× 6
Otocinclus vittatus
Streams across South America · stream
Photo: No machine-readable author provided. Chle assumed (based on copyright claims)., CC BY-SA 3.0
× 6
Fed algae wafers until the tank grew enough biofilm.
Neocaridina davidi
Streams of Taiwan and eastern China · stream
Invertebrate. Many fish will eat it, so choose tank mates with care.
Photo: TonyZimbinski, CC BY-SA 4.0
× 10
The colony has tripled.
Every species is comfortable in this range.
No two species here can cross, so any fry that turn up are pure.
Workable with strong filtration and weekly large water changes, but leave room for fry that grow up in the tank.
Size and stocking checks use a typical tank of the size you picked. Add the real length and volume for a sharper answer.
Care data for Cherry shrimp, Neon tetra, Otocinclus, Panda corydoras is estimated or taken from the genus, not yet checked against a source.
