Air Pump

An air pump is a simple but essential piece of aquarium hardware. It pushes air through tubing into the tank, where it exits through an airstone, sponge filter, or other air-driven device. The rising bubbles create surface agitation, which promotes gas exchange — bringing oxygen in and releasing CO2.

Why Use an Air Pump?

Oxygenation

In densely stocked tanks or warm-water setups, dissolved oxygen can drop to dangerous levels. An air pump increases surface agitation, improving the rate at which oxygen dissolves into the water.

Powering Sponge Filters

Sponge filters are entirely air-driven. Without an air pump, they cannot function. This makes air pumps essential for breeding tanks, hospital tanks, and shrimp setups.

Night-Time CO2 Management

In planted tanks running pressurised CO2, oxygen levels drop at night when plants switch from photosynthesis to respiration. Running an air pump on a timer during lights-off prevents oxygen crashes and protects livestock.

Emergency Backup

Battery-operated air pumps are critical during power outages. They keep water oxygenated and filters running when electricity fails.

Types of Air Pumps

| Type | Noise Level | Output | Best For | |---|---|---|---| | Diaphragm (Standard) | Moderate | High | Large tanks, multiple outputs | | Piezoelectric | Ultra-quiet | Low–Med | Bedrooms, nano tanks | | Battery Backup | Variable | Low | Power outage emergencies | | Linear Piston | Low | Very High | Fish rooms, multiple tanks |

Sizing Your Air Pump

A general rule is 1 watt per 40 litres of aquarium volume. However, the actual requirement depends on:

• Depth: Deeper tanks need more pressure to push air to the bottom.
• Accessories: Airstones, sponge filters, and multi-way splitters all increase demand.
• Altitude: Higher altitudes reduce pump efficiency.

Key Accessories

• Airline Tubing: Standard 4/6mm silicone tubing connects the pump to in-tank devices.
• Check Valve: A one-way valve that prevents water from back-siphoning into the pump if it stops. Essential for safety.
• Gang Valve: A multi-port splitter that lets you control airflow to multiple devices from one pump.
• Airstone: A porous stone that breaks the airflow into fine bubbles for better diffusion.

Trusted Brands

• Tetra Whisper: A long-standing budget favourite, very quiet.
• Eheim: Premium German engineering, ultra-silent operation.
• Hygger: Excellent value with adjustable output and low noise.
• USB Nano Pumps: Compact, USB-powered options ideal for nano tanks.

Pros & Cons

Advantages

• Affordable: One of the cheapest pieces of aquarium hardware.
• Versatile: Powers sponge filters, airstones, ornaments, and more.
• Life-saving: Critical oxygenation during power outages (battery models).
• Simple: No plumbing, minimal setup.

Considerations

• Noise: Cheaper models can be rattly and vibrate against surfaces.
• CO2 conflict: Running an air pump during CO2 injection will off-gas dissolved CO2.
• Aesthetics: Airline tubing and airstones can be visually intrusive.
• Maintenance: Diaphragms wear out over time and need replacement.