Cardinal Tetra: Tank Size, Tank Mates and Setup
Like a neon tetra with a full red stripe, and happier in warmer water. Keep six or more in 20 gallons or larger.
- Minimum tank
- 20 gallons
- Temperature
- 75–82°F
- Group size
- 6 or more
- Adult size
- 2 inMiddle of the tank
- Likes warmer water than neon tetras, which makes it a good match for angelfish and rams.
Paracheirodon axelrodi. Figures are commonly published care ranges; see how it works.
How many cardinal tetras per tank size
The most you could keep if cardinal tetras were the only species. Open a size in the builder to add tank mates.
| Tank | Cardinal tetra, kept alone | |
|---|---|---|
| 5 gallon | Too small (needs 20+ gal) | |
| 10 gallon | Too small (needs 20+ gal) | |
| 20 gallon | Up to 18 | Plan this tank |
| 29 gallon | Up to 29 | Plan this tank |
| 40 gallon | Up to 40 | Plan this tank |
| 55 gallon | Up to 55 | Plan this tank |
| 75 gallon | Up to 75 | Plan this tank |
What you need for cardinal tetras in a 20-gallon tank
A starting setup: 6 cardinal tetras in the smallest standard tank that suits them.
20-gallon tank
- These fit a 20-gallon tank and get along. Aim for about 79°F.
Equipment, sized for this tank
Starter supplies
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Cardinal tetra tank mates
These share a temperature range and temperament with cardinal tetras, with no warnings from our checks.
Use caution with: white cloud minnow, fancy goldfish. Add them in the builder to see why.
Plan a tank around cardinal tetras
Add tank mates, check the stocking level and get the equipment sized for your tank.
Open the tank builderCardinal tetra questions
What size tank does a cardinal tetra need?
At least 20 gallons for a group of 6. A larger tank is more stable and gives you more choice of tank mates.
How many cardinal tetras can I keep in a 20-gallon tank?
Up to about 18 if they are the only species in the tank. Fewer if you add other fish.
Do cardinal tetras need a heater?
Usually yes. Cardinal tetra does best at 75–82°F, which is warmer than most rooms. A 20-gallon tank needs about 100 watts in a 68°F room.
What fish can live with cardinal tetras?
Good matches include bettas, neon tetras, ember tetras, rummy-nose tetras, black skirt tetras, guppies. They share a temperature range and temperament with cardinal tetras.