Aqua One Flexible Aquarium Airstone - 30cm The Aqua One flexible air stones are a great way to aerate your aquarium. By breaking the surface tension of the water, oxygen may be absorbed into the water. Filtration system performance and overall water quality will be greatly improved with a greater oxygen content in the water. Bend into any shape you need to create the look you desire Increases water circulation Bubbles make a great feature in any aquarium Create less back pressure than traditional air stones, which reduces damage to your air pump Tips To achieve the look you desire from your airstone, the longer the airstone, the bigger the air pump needs to be operate it.