Best fish for a 20 gallon tank

Why 20 gallons works well

A 20 gallon gives room for a small school of tetras or rasboras, corydoras, and a centrepiece. Water is more stable than in smaller tanks. See how many fish per gallon and overstocking. Try our free stocking calculator.

Stocking ideas

• Six to eight neon tetras, six corydoras, and a dwarf gourami.
• One betta with a small school (see betta tank mates).
• Livebearers: guppies or platies; they breed so plan for offspring.

Quick takeaways

• 20 gallons suits schooling fish, corydoras, and a centrepiece.
• Stock gradually; test water and do regular water changes.