🪵 Cylindrical air stones: oxygenate your roots with finesse
Dissolved oxygen is the number one limiting factor of a successful hydroponic grow. The more oxygen-saturated the solution, the better the roots breathe, the more nutrients they absorb and the faster the plant grows. Air stones are the basic tool to reach this saturation: paired with an air pump, they turn an air flow into thousands of microbubbles that stay suspended long enough to transfer their oxygen to the water.
Growrilla stones use a particularly fine grain that produces bubbles under 1 mm. Compared with a standard coarse-bubble stone, the oxygenation yield is up to 40 percent higher at equal air flow.
📊 Technical specifications
- Quantity: 10 stones per pack
- Sizes: 50 x 50 mm (diameter x height) or 100 x 50 mm
- Fitting: 4 mm barbed for standard silicone tubing
- Material: fine-grain sintered ceramic
- Recommended air flow: 100 to 300 L/h per stone
- Lifespan: 6 to 12 months depending on water hardness
- Country of origin: Italy
🎯 Which size to choose
The 50 x 50 mm size is the standard supplied with Growrilla RDWC 2.0 and PRO kits. It fits in a 19 L bucket and works with the stock Hailea ACO 9602 air pump. For preventive replacement (stones clog up over the months), the pack of 10 covers an 8-bucket kit for about a year.
The 100 x 50 mm size is meant for large volumes: buffer reservoirs, aquaponic tanks, mixing tanks or oversized grow buckets. A more powerful air pump is needed to get the most out of them (250 L/h minimum per stone).
🧽 Stone maintenance
A healthy air stone produces a dense cloud of uniform microbubbles. When the bubbles become large and irregular, the pores are clogged with mineral salts.
The fix: soak the stone in distilled water + 1 ml of food-grade citric acid for 30 minutes, then brush gently. If after two cleanings the output does not come back, it is time to replace.
💡 Pro tips: optimising oxygenation
Golden rule: 1 stone per grow bucket, placed at the bottom so the bubbles rise in a column along the roots. In a mixing tank or buffer reservoir, fit 2 to 3 stones in parallel to cover the whole volume.
To go further: feed each stone with its own line from a distribution manifold rather than in series. You guarantee equal flow on all stones and easy individual disconnection.
