Sleep Posture
Arowana sleep near the middle of the tank, body slightly tilted at 10-20 degrees, fins barely moving. Breathing slows to 20-30 gill cycles per minute.
They never fully lie down. If your arowana is resting on the bottom, something is wrong — check oxygen, parameters, and for swim bladder issues.
Ideal Dark Hours
10-12 hours of full darkness per night. Use timers to ensure consistency. Shifting schedules stresses the fish over weeks.
Dim the room before lights-out. Arowana startle-flip if plunged into sudden darkness from bright light.
Moonlight LEDs (Optional)
Blue "moonlight" LEDs (5% intensity) let you observe nighttime behavior without disturbing sleep. They don't count as full daylight for circadian rhythm.
Turn off moonlight if you notice the fish still active at 2-3am — they're not resting properly.
Signs of Poor Sleep
Constant night swimming, gulping at surface, scraping on decor = tank stress or disease. Address root cause, not symptoms.
Healthy arowana wake at dawn, patrol the tank, and beg for food at feeding time.