About
Aquarium Stocking Calculator is a comprehensive, free online planning tool designed for both beginner and experienced aquarium hobbyists. Powered by the Fishi platform, it provides access to a database of over 800 freshwater and tropical fish species to help users make informed decisions before stocking their tanks. The tool's Tank Planner lets users build out a complete aquarium livestock plan, factoring in tank size and the specific needs of each species. Compatibility checking helps identify potential aggression issues or mismatched water parameter requirements — a critical step often overlooked by new fishkeepers. The built-in unit converter makes switching between litres and gallons seamless for users worldwide. The calculator is honest about its limitations: results are estimates, not guarantees, as fish behavior can vary significantly between individuals. The tool encourages users to treat its output as a starting point and to research each species independently before purchasing. This responsible approach makes it a trustworthy reference rather than a prescriptive authority. Ideal for hobbyists setting up a new tank, rehoming fish, or expanding an existing community aquarium, the Aquarium Stocking Calculator reduces the guesswork and helps prevent common mistakes like overstocking — which can lead to poor water quality, stress, disease, and fish loss. Its clean, no-registration, browser-based interface makes it instantly accessible to anyone.
Key Features
- 800+ Fish Species Database: Browse and select from a database of over 800 freshwater and tropical fish species, each with specific care and compatibility data.
- Tank Capacity Calculator: Estimate how many fish your tank can safely support based on tank size and the space requirements of each selected species.
- Fish Compatibility Checker: Identify potential compatibility issues between species, including aggression, size mismatches, and differing water parameter needs.
- Litres & Gallons Converter: Seamlessly switch between metric and imperial units so hobbyists anywhere in the world can use the tool without manual conversions.
- Interactive Tank Planner: Build a complete livestock plan for your aquarium visually before making any purchases, helping avoid costly stocking mistakes.
Use Cases
- Planning the livestock for a brand-new freshwater aquarium before purchasing any fish.
- Checking whether two or more fish species are compatible before adding new fish to an existing tank.
- Calculating whether a specific tank size can safely accommodate a desired fish community without overstocking.
- Researching the care requirements and temperament of unfamiliar fish species prior to purchase.
- Teaching beginner fishkeepers responsible stocking practices and helping them avoid common beginner mistakes.
Pros
- Completely Free: No registration, subscription, or payment required — full access to all features at no cost.
- Large Species Database: With 800+ species, the tool covers a wide range of common and less common freshwater and tropical fish, making it useful for diverse setups.
- Responsible & Transparent: The tool clearly communicates that results are estimates and encourages further research, building trust and promoting responsible fishkeeping.
Cons
- Estimates Only: Results are approximations and cannot account for every individual fish's behavior or tank-specific variables, requiring supplemental research.
- Limited to Listed Species: Users keeping rare or uncommon species not in the database may not be able to fully plan their tank using this tool alone.
- No Account or Save Feature: There is no apparent way to save or share custom tank plans across sessions, which can be inconvenient for ongoing planning.
Frequently Asked Questions
Is the Aquarium Stocking Calculator free to use?
Yes, the calculator is completely free with no account or subscription required. Simply visit the website and start planning your aquarium immediately.
How many fish species are in the database?
The database includes over 800 fish species, covering a wide range of freshwater tropical fish commonly kept in home aquariums.
Can I use it with litres or gallons?
Yes, the tool supports both litres and gallons, so you can enter your tank size in whichever unit you prefer.
Are the stocking recommendations guaranteed to be accurate?
No — the tool provides estimates based on general guidelines. Fish behavior varies between individuals, so the calculator should be used as a starting point alongside species-specific research.
What is Fishi?
Fishi is the platform that powers the Aquarium Stocking Calculator, providing the underlying fish species data and compatibility logic behind the tool.
