Adult size and space
Compare mature size and minimum volume before purchase size.
Freshwater fish
compatibility checker.
Screen the fish's adult needs first. Then add your water and current livestock for a more useful tank-aware comparison.
No signupSaved locallyFreshwater focused
Does this tank meet the fish's size minimum?
Start with adult size and the catalog minimum. No account or email is required.
Your result will explain the adult-size screen and the next context worth checking.
Compatibility is about your tank, not a generic list.
The quick result checks adult size against a catalog minimum. The complete TankWise preview adds the tank details that a simple species-to-species chart leaves out.
Water overlap
Review temperature and pH against the aquarium baseline.
Current livestock
Include group sizes, temperament, and predator-prey signals.
Projected load
Estimate the effect of the proposed adult fish on the tank.
Save. Understand. Compare. Reassess.
Add the aquarium you actually own, including its water and current livestock. The detailed preview then screens a proposed fish across adult size, water overlap, projected load, social needs, and selected predator-prey signals.
Start by saving the aquarium profile.
Step 01
Save the aquarium first.
These setup details become the context for water, livestock, plants, and every later fish comparison.
Tank setup
Your next step is the aquarium's water baseline.
Freshwater compatibility questions
Can a fish compatibility checker guarantee fish will get along?
No. A checker can compare catalog traits and saved tank details, but individual behavior, territory, health, sex, age, breeding state, filtration, and aquarium layout can change the outcome.
Why does this quick check start with adult size?
Many fish are sold as juveniles. Adult size affects space, waste, turning room, predation risk, and the long-term suitability of the aquarium.
What should I check after aquarium volume?
Review tank dimensions, temperature and water overlap, current livestock, social group size, territory, projected load, and predator-prey risk.
See exactly how the estimates work in the TankWise methodology.