Why a Golden Arowana Bubbles at the Water Surface, and What to Do

1 Why Arowana Blow Bubbles at the Surface and How to Fix It

1. Low Oxygen

Bubbling at the surface can mean low oxygen. When the tank is oxygen-poor the arowana floats to the top or blows bubbles, even poking its mouth above the water as if breathing air.

Fix: Change part of the water — fresh water holds more oxygen, but swap only about a third at a time. If possible, add an air pump to keep oxygen high.

2. Water Quality and Temperature

Although arowana aren’t very demanding, poor water that shifts pH or water that’s too cold can stress them and make them bubble at the surface.

Fix: Warm the tank to about 25°C (their ideal) and refresh the water, keeping pH at 6.5–7.0 — slightly acidic.

3. Indigestion

Like hiccups in people, indigestion produces gas in the gut; once it builds up, the fish releases it through the mouth to balance pressure. This usually comes from overfeeding or hard-to-digest food.

Fix: Fast the fish for three days, then feed easy foods like aquatic plants or cooked millet. If bubbling continues, it can’t digest the food — give a mild digestive aid.

The above covers why a golden arowana bubbles at the surface and how to help.