The best replacement for tetras is neon tetras.

The best alternatives to tetras are rated as following:
★★★★★  neon tetras
★★★★  cardinal tetras
★★★  cardinal
★  guppies
★  danios

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

Other search terms related to tetras and their ratings are:
★★★★★ betta
★★★★ angelfish
★★★ cichlids
★★ tiger barbs
★★ guppies
★★ discus
★ danios
★ mollies
★ barbs
★ gouramis
★ bettas
★ betta fish
african cichlids
You have in mind a companion for tetras and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of tetras in all years. Click on graph for more.
tetras
neon tetras
cardinal tetras