Air stone Tetra AS 35 by Tetra — aquarium aeration stone AS 35

Tetra AS 35 is an aquarium air stone engineered to create a steady stream of fine bubbles that enhance oxygen transfer and water circulation. Designed for compatibility with standard airline tubing and common aquarium air pumps, the AS 35 supports biological filtration and promotes a stable environment for both freshwater and saltwater aquaria. The compact design allows placement near filters, inside sump chambers, or directly in the display to boost gas exchange and reduce dead zones.

Advantages

The AS 35 produces uniformly sized fine bubbles that increase the contact area between water and air, improving dissolved oxygen levels without excessive surface disturbance. Its durable construction resists clogging under normal aquarium conditions and maintains consistent airflow when used with appropriately sized pumps and tubing. The stone’s size and shape make it easy to position for targeted circulation and it integrates with existing aeration setups.

Suitable for

• Aeration in small to medium freshwater aquaria
• Supplementary oxygenation in marine tanks and reef systems
• Improving circulation near filters, heaters, or plant beds
• Promoting gas exchange in sumps and refugia

Key specifications

• Function: generates fine bubbles for aeration and circulation
• Compatibility: standard airline tubing and aquarium air pumps
• Application: suitable for freshwater and saltwater setups
• Installation: inline placement or fixed position inside tank or sump
• Material characteristics: porous diffuser element designed for even airflow

How to use

Connect the AS 35 to an aquarium air pump using suitable airline tubing and ensure the pump capacity matches the tank volume and desired bubble output. Place the stone where increased oxygenation or circulation is needed — for example near the filter outlet, heater, or plant area. If the stone is used in a sump, position it to create gentle flow through the filtration stages. Adjust pump flow or add an air control valve to regulate bubble size and volume. Periodically inspect the diffuser for signs of clogging and clean or replace it if airflow becomes restricted.

Usage recommendations

For reliable performance, use the AS 35 with an air pump appropriate for your aquarium size and consider adding an inline check valve to prevent backflow. Regular maintenance such as gentle brushing or soaking in dechlorinated water can prolong service life; avoid aggressive cleaners that could damage the porous surface. Monitor dissolved oxygen and fish behaviour to confirm the aeration level is suitable for your specific setup.