Hobby Vulcano Volcanic Rock Airstone

Hobby Vulcano Volcanic Rock Airstone is a genuine piece of volcanic rock, roughly 11x8cm, drilled for an airline. The natural pores do the diffusing, so it aerates and looks like part of the hardscape at the same time.

Key Features

• Real Volcanic Rock, so every piece is a different shape.
• About 11x8cm.
• Decor And Diffuser In One: no plastic airstone sitting in the open.
• Variable Bubble Pattern, because the pores are natural rather than machined - part of the charm, not a fault.

What Aeration Does, And Does Not Do

• It mostly works by moving the surface. Gas exchange happens at the water surface, not on the bubbles. A bubble stream drags water up to the surface and that is where the oxygen actually gets in.
• It matters most in warm water. Warm water holds less dissolved oxygen, so a tank at 30C needs more surface movement than the same tank at 24C. In a UAE summer that is not a small effect.
• It does not cool the water. In UAE summers the problem in most tanks is too much heat, not too little. Aeration helps a warm tank because warm water holds less oxygen - but it does not cool it. If your tank runs above about 30C you need a fan or a chiller, not more air.
• It does not replace a filter. An airstone oxygenates; it does not remove waste.

Good To Know

• This listing is as described above.
• You need an air pump and airline, and neither is included. This is the diffuser only. A non-return valve or a pump mounted above the water line also stops water siphoning back into the pump if the power goes off.
• Airstones clog. When the bubbles get coarse or one-sided, soak the stone in a weak vinegar solution, rinse it well and refit - or replace it, they are cheap.
• Mount the pump above the water line if you can. Then even without a valve, water cannot siphon back.
• An air pump buzzes. Standing it on a folded towel rather than a hard shelf makes more difference than any anti-vibration gadget.