Collection: Airstones & Diffusers

Bar stones, disks and ceramic diffusers

A bar stone is the standard shape and the easiest to hide behind a sponge filter or a rock. Length sets the spread: a 1.5 inch stone suits a quarantine tub or a betta tank, while a 12 inch bar runs the width of a larger aquarium. Round disks sit flat on the substrate and send bubbles up in a wide cone rather than a line. Ceramic diffusers produce a smaller bubble than a moulded stone, which is the usual reason for choosing one.

Matching a stone to the pump

• The finer the pore, the more pressure the pump has to supply.
• Deeper tanks need more from the pump than shallow ones at the same stone size.
• A control valve lets a single stone be trimmed back without straining the pump.
• Splitting one pump across several stones drops the output at each.

Replacing a stone

Airstones load up with mineral deposits and biofilm and gradually pass less air, which is normal wear rather than a fault. Keeping a spare on hand is the simplest approach, and buying multi-packs of the smaller sizes works out easier for anyone running several tanks. Rinse a new stone before it goes in and give it a minute to soak so it wets through evenly.