How Many Fish Can I Keep in a 29-Gallon Tank?
Find the recommended maximum number of 2-inch fish for a 29-gallon aquarium.
How to use this tool
- Enter your tank volume in US gallons (use the Aquarium Volume Calculator if needed).
- Enter the typical adult length of the fish species in inches.
- The result is the approximate maximum number of fish.
- Always research specific species needs — filtration, territory, and water chemistry matter more than this rule alone.
The 29-gallon tank is a common step up from a 20-gallon — calculate how many fish it can safely accommodate.
Frequently asked questions
- Is the one-inch-per-gallon rule accurate?
- It is a rough guideline only. Larger, messy fish (e.g. goldfish, cichlids) produce more waste per inch than small tropical fish. Always consider filtration capacity and species behaviour.
- How many fish can I put in a 10-gallon tank?
- Using the 1-inch-per-gallon rule with 1.5-inch fish: 10 ÷ 1.5 ≈ 6 fish. In practice, a 10-gallon is better suited to 5–6 small fish such as neon tetras.