Collection: Airstones & Diffusers

Shapes and where they suit

Bar stones are the default: easy to tuck behind a sponge filter, a piece of rock or a plant, and available short enough for a quarantine tub or long enough to span a display. Flat disks work differently - they sit on the sand or gravel and push a wide cone of bubbles upward, which suits a tank where a single visible column is wanted. Ceramic diffusers are the choice when the bubble size itself is the point.

Pump pairing

• Smaller pores need more pressure behind them than coarse ones.
• Water depth adds to the demand on the pump at any given stone size.
• Trimming a line with a control valve is gentler on a pump than restricting it at the outlet.
• Feeding several stones from one pump reduces what each one receives.

When to swap one out

Deposits and biofilm build up inside the pores over time and airflow tapers off. That is expected wear, not a defect, and the usual fix is a replacement rather than a repair. Multi-packs in the smaller sizes make sense for anyone running a rack of tanks. Soak a new stone briefly before installing it so the whole surface wets through and bubbles evenly from the start.