Step 1: Verify Both Sexes Present
Many species are hard to sex. Confirm with a second opinion or wait for full mature coloring.
Two females or two males sometimes look like a pair but will never spawn.
Step 2: Verify Maturity
Under-size fish rarely breed. Check expected adult size vs current.
Aggressive mature male paired with immature female will stress-kill her before spawning.
Step 3: Water Parameters
Check hardness, pH, nitrate, and temperature against species requirements.
Nitrate above 40ppm suppresses breeding in most species.
Step 4: Conditioning
High-variety diet with 60%+ live or frozen for 4 weeks preceding spawn attempts.
Flake-only diets rarely produce spawns in demanding species.
Step 5: Trigger Variety
If normal triggers fail, try extreme water change (50% cool water drop).
Separation and re-introduction after 2 weeks.
Larger tank with more visual barriers.
Step 6: Different Pair
Some individuals simply do not breed. Swap in a different male or female.
Record the non-breeder as retired — do not keep trying indefinitely.