The best replacement for tetra is p25.

The best alternatives to tetra are rated as following:
★★★★★  p25
★★★★★  quad
★★★  mopho x4
★★★  iden
★★★  prophet 08
★★  aqueon
★★  dera
★★  boltor
★★  apco
★★  tetrapol
★★  karak
★★  mopho
★★  neon tetra
★★  analog four
★★  cardinal tetra
★  danio
★  evolver
★  dmr
★  slim phatty
★  top fin
★  marineland
★  neon tetras
  prophet
  tera
  blofeld
  quadra
  guppy
  cardinal
  sera

Your alternative for tetra is not listed? Suggest!
Speaking about tetra, one probably shouldn't forget about betta.

Other search terms related to tetra and their ratings are:
★★★★★ betta
★★★ guppies
★★ angelfish
★ discus
You have in mind a companion for tetra and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of tetra in all years. Click on graph for more.
tetra
p25
quad