Hobby Pond Airstone - 5cm

Hobby Pond Airstone - 5cm is a 5cm airstone built for pond use, which means it is heavier and coarser than a tank stone and keeps working in water with silt and algae in it.

Key Features

• 5cm Diameter, and weighted enough to stay on the bottom of a pond.
• Fine Bubbles: fine bubbles transfer oxygen better than big ones, because more bubble surface meets the water.
• Built For Outdoors: designed to survive pond conditions rather than clean aquarium water.

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.