What we can’t tell you.

We haven’t personally kept every species

Fish profiles range from “we’ve cross-checked five sources and seen the species in person” to “we’ve read the references but haven’t kept this one ourselves.” The fish page tells you which is which.

Low-confidence species carry a visible note saying so. We don’t pretend our research is lived experience. If you’ve kept a species we haven’t and you spot something wrong on its profile, email us.

Real tanks vary

A pair we flag as CAUTION is kept successfully by experienced keepers all the time. Big planted tank, careful introduction order, dominant individuals removed, the right substrate. Our verdict is what to expect from an average setup, not what’s possible in a brilliant one.

The reverse is also true. A pair we call GOOD can still fail if your fish are stressed for any reason the engine can’t see. If your tank tells you the verdict is wrong, the tank wins.

We don’t model

• Individual personality. Two bettas from the same shop tank behave nothing like each other.
• Filter maturity or nitrogen cycle. Compatibility doesn’t replace cycling your tank.
• Disease. A perfect pair on paper can still arrive carrying ich, columnaris, or worse. Quarantine.
• Specific tap water. We give a shared pH and temperature window. We can’t check what comes out of your cold tap.
• Tank layout. Line of sight, sight breaks, vertical territory, hides per fish — all matter, none modelled.
• Introduction order. Adding a betta to a cory tank is different from adding cories to a betta tank.

Sources can be outdated

Husbandry numbers in print can lag behind what experienced keepers know. We try to cite recent, reputable references (Seriously Fish, FishBase, Practical Fishkeeping) but a 2010 source can still be on file for a species that hasn’t been re-examined since.

If you see a number on our site that conflicts with a more recent peer-reviewed or expert source, email us. We’ll update the profile and log the change on the methodology page.

Use this as a planning floor

Fishori is most useful for the question “is this mix obviously wrong before I pay?” It’s good at that. It catches the predation traps, the impossible water windows, the long-fin + nipper combos, and the schoolers-of-one mistakes.

For the question “will my specific setup work long-term?”, you need a real keeper who has seen your tank and your fish. We can’t replace that. We don’t try to.