Aeration FAQ's

Will aeration control algae and weed problems?

Algae obtain their nutrients from the water, while submerged weeds typically obtain nutrients from root systems in the soil of the lake bottom. Aeration would have no effect on the rooted plants, but it can have a profound effect on the algae, depending upon many circumstances. In the right situation, a well-designed aeration system will greatly reduce algae primarily by reducing nutrient cycling from the formerly anaerobic bottom. As the water clarity improves, the plant community may shift to submerged weeds.

When oxygen is used up too quickly in the water problems can occur:

  • Oxidation of organic wastes slows down increasing bottom muck
  • Anaerobic bacteria break down organic materials, creating toxic gasses such as hydrogen sulfide
  • Nutrients build up, increasing the growth of algae. Many of the worst algae species including the 'toxic' ones prefer high pH still-water habitats
  • Fish cannot breathe, resulting in stress and possible mass fish kills
  • The water becomes stratified with temperature differences between the top and bottom levels further reducing oxygen at the lower levels

Will aeration help prevent fish kills?

Yes. The circulation provided by lake bed aeration systems prevents stratification or layering of the water column. It is this layering that leads to dissolved oxygen depletion in the lower layers of your pond. Since most fish kills are caused by low dissolved oxygen levels many fish kills can be prevented. However fish kills are still possible due to other factors.

Why Aeration?

Proper aeration is essential to maintaining the health of your pond or lake.

  • Aeration improves water chemistry and clarity
  • Aeration is a leading way to prevent fish kills
  • Aeration helps support fish and microphyle health
  • Aeration can be effective in controlling certain types of weed and algae

Will aeration improve water quality and clarity?

Only when aeration is done correctly will it improve water quality and water clarity. All lakes are different and they often need an engineered approach. When a stratified lake is destratified, water quality is improved by reducing the nutrient cycling and increasing the assimilation capacity. In some lakes with very clear surface water, destratification can reduce water clarity.

If water clarity is the goal, the benefits are aesthetics. The cause could be the source of a bigger problem, or it could be from a discharge requirement. When reduced clarity is the goal, it’s for weed control measurement or enhancement of the fish population. We can use pond dyes to artificially block sunlight, thus limiting weed growth; we can also use pond fertilizers to produce algae blooms that serve as food source for bream fry,  which improves recovery rate.

How long will it take for aeration to improve a lake?

In general, the time will vary between 2 and 12 months before visually significant improvements are reached. If the lake is a good candidate for aeration, and if the aeration system is designed correctly, it will definitely continue to improve the water clarity year after year, unless more nutrients re added.

What is the difference between a display fountain and an aerating fountain?

Display fountains generally have one use, and that’s for looks. Generally, these patterns are multi-tiered or they have very tall or wide patterns. Aerating fountains have dual purpose: they want to aerate, but you also have a nice pattern for looks. These patterns are generally limited to cone shaped patterns.

Lake Fountain and Aeration Systems

Fountains can be an efficient form of aeration. Another option is the use of an air diffuser system. Although air diffuser systems have lower electrical costs than fountains, they offer little aesthetic value because most of the aeration process takes place under the water. 

What is the difference between surface and submersed aeration? 

A surface aerator is a device that takes water from the vicinity of the surface and throws it into the air, where it picks up atmospheric oxygen. Submerged aeration typically uses air bubbles that are released below the surface and give up the oxygen they contain as they rise. Another method is the Synergistic Technique. It destratifies and puts oxygen on the bottom where it will improve the overall water quality of the lake. Surface aeration is excellent in an emergency. It can quickly put a lot of oxygen in a small area where the fish can come to survive. Never use submerged aeration systems in an emergency, as the oxygen put in is diluted throughout the water column and the higher oxygen levels normally found on the surface are made lower by upward pulsing bottom water.

What is an aerator?

An aerator is generally a mechanical device used to move water that will improve dissolved oxygen levels. Common aerators or air diffuser systems, paddlewheel systems, or pump systems are running off of electricity, solar power or even wind-driven devices.


Excessive plant growth can result in cloudy water and even a foul odor. Reducing the amount of algae and, thus, the amount of excess plants can be achieved by introducing various fish, herbicides or even aeration solutions into the pond.

Other Treatment Options

Certain types of fish, including some types of carp and Tilapia, can decrease the amount of algae in a pond or lake, as algae is a primary component of their diets. 

Stagnation can also result in algae-filled water. Providing aeration through a fountain or underwater diffuser system can disrupt the peaceful water in which algae thrives.

Water Garden Aeration