How many questions are in this quiz?

This quiz has 126 questions focused on aquarium fish compatibility and stocking rules.

What format is the quiz in?

Each question is multiple-choice with 4 options, and there’s no timer.

Can I choose the number of questions and difficulty?

Yes. You can set your preferred question count and pick a difficulty level; the question pool is mixed overall.

Does the quiz cover community tanks and aggressive fish?

Yes. It includes community setups, semi-aggressive species, territorial behavior, and common mismatch scenarios.

What common mistakes will this help me avoid?

It targets pitfalls like overstocking, ignoring adult size, mixing incompatible water parameters, and keeping schooling fish in too-small groups.

Online Quiz: Aquarium Fish Compatibility

About this quiz

What you’ll practice

Compatibility isn’t just “can they live together?”—you’ll practice matching temperament, adult size, schooling needs, and water parameters to build stable stocking plans.

Expect scenarios about community fish, semi-aggressive species, bottom dwellers, and invertebrates, plus how filtration and tank footprint change what’s realistic.

Format and difficulty controls

Each question has 4 options and there’s no timer, so you can think through trade-offs like territory, bioload, and group sizes.

You can choose how many questions to play and set the difficulty; the overall pool is mixed, balancing quick fundamentals with trickier edge cases.

Common pitfalls this quiz targets

Many stocking problems come from underestimating adult size, ignoring social structure, or mixing fish with incompatible temperature/pH needs. The quiz highlights these frequent missteps so you learn to spot them before they become losses.

Confusing “peaceful” with “won’t nip fins” or “won’t be outcompeted for food”
Overcrowding by counting inches per gallon without considering body mass and activity level
Mixing schooling species in too-small groups, causing stress and aggression
Ignoring tank footprint and territories (especially for cichlids and bottom dwellers)
Combining fish with mismatched temperature, hardness, or flow requirements

How the challenge stays fair

Difficulty is balanced by mixing straightforward rules (like minimum group sizes) with situational questions where more than one choice seems plausible. When in doubt, prioritize long-term adult needs, stable water quality, and natural behaviors over short-term “it might work.”