Proper Aeration in Saltwater Aquariums is Critical


How effective are the little bubbles that emerge from or diffusers? Many aquarists feel they serve a significant part in the oxygenation and aeration of the water in an aquarium, and that this air supply is sufficient. Not so! When it comes to increasing DO (dissolved oxygen) in an aquarium, one of the most important sites for this exchange is the water surface. is dissolved in the water, carbon dioxide is discharged into the atmosphere, and other gases travel through the porous surface of the water with ease. When we breathe, our bodies function on this principle: good air in, bad air out. The same is true for your tank.

Air Stone Pros

So, if the water surface area of an aquarium is where the main exchange of gasses occurs, then why use air stones and have bubbles in an aquarium at all? Because they do have their benefits.

  • They are used to drive various types of filters and equipment, such as under gravel filters and some types of protein skimmers.
  • Tanks that have solid covers or close-fitted hoods on top are prime candidates for stagnant air, low oxygen levels, and high levels of carbon dioxide. However, for these types of setups that have an under gravel filter powered , the fresh air bubbles that come up from the uplift tubes help to eliminate these problems by provided excellent oxygen and other gas exchange opportunities. A powerhead can be used and stones to run the under gravel filter, but if the powerhead is not equipped with an aeration feature, or this feature is not used, it can result ¬†and low pH.
  • Whether using an under gravel filter or not, air bubbles help to move the tank water vertically towards the surface, assisting with oxygen and other gas exchanges.
  • They are a cheap way to move the tank water vertically.
  • They do create a wall of bubbles that can look pretty cool in an aquarium, not to mention that watching them can be quite soothing.

Ceramic, glass, and, increasingly, wood are used to create air stones. Wood stones may be easily created at home using a variety of widely available woods, the most popular of which being limewood. This sort of air stone is said to be perfect for air-driven and is quite easy to construct. These air stones, as well as limewood air diffusers from Lee's Aquarium & Pet Products, are available on the market.

Air Stone Cons

Ok, so air stones do have some benefits, but are there any downsides to their use? Yes.

  • They are not as efficient as powerheads, water pumps, and/or protein skimmers are at creating water movement in an aquarium. All of these are much better at helping with oxygen and other gas exchanges at the water's surface.
  • They do not move water fast enough or inadequate volume for what a tank usually needs for good all-round, vertical and horizontal, . This situation can also contribute to a low or (gallon per hour) tank water turnover time.
  • They create a lot of salt spray, that in turn contributes to salt creep problems.
  • They clog up.
  • They wear out quickly and usually need replacing often.
  • They can give off irregular airflow.
  • Airline hoses can get pinched or kinked, which weakens or cuts off the airflow.
  • Many times the air pump chosen to run air stones is inadequate, resulting in low airflow pressure.
  • Some airflow pressure is lost the longer the distance the air has to travel through the clear tubing from the air pump to the air stones.
  • The deeper the tank water, the farther the air has to be pushed downhill to reach the air stones, resulting in loss of airflow pressure.

If you are using air stones for the sole purpose of aeration in an aquarium, this may not be enough.