Does a fountain aerate a garden pond

Yes, a fountain can aerate a garden pond to some extent, but it’s not as effective as using a dedicated air pump.

We all like a fountain, it’s a soothing addition to a pond, the sound of the water splashing on a perfect summers day is very relaxing, not to mention mesmerizing, but how much can it aerate your pond.

You would think that all that splashing would stir up the water enough to add a good amount of oxygen to your pond.

The problem with fountains is they only aerate about 30-60 cm (1-2 feet) of the surface of the pond water, this is great for plants and fish that come to the surface of your pond, but not so good for aerating the bottom of your pond, this could cause stratification.

Stratification is when a pond only absorbs oxygen and heat at the surface of the pond water, as the pond gets deeper the water gets colder, the colder the water gets the more it gets deprived of oxygen, you eventually end up with two separate layers of water in your pond, a warm upper layer with plenty of oxygen in it and a cold lower layer with less oxygen, you will notice your fish staying in the top layer of your pond if your pond is stratified.

A fountain works by pumping water from the pond into the air, the droplets of water that are produced collect oxygen from the air, it’s these droplets that add oxygen to your pond when they land back in your pond.

This all sounds good, but what these fountains are doing is just recirculating surface water that is already rich in oxygen, they are not oxygenating the deeper parts of your pond where oxygen is needed most.

There are two types of aeration, bottom and surface, the problem with fountains they are usually surface aerators, the best type of aerator are the ones that lifts the water from the bottom of your pond in tiny air bubbles, this mixes all the water in your pond and prevents stratification.

You can get fountains that float on the pond surface or submersible fountains that sit just below the surface of the water.

Floating fountains are limited to the surface of the water they are sitting on while submersible fountains are limited to the length of the spout, some spouts are adjustable in length but even then they will never be long enough to recirculate water from the bottom of the pond.

Obviously a lot depends on the depth of your pond, anything deeper than 1.8 m (6ft) is a no no when it comes to a fountains ability to draw water from the bottom.

You might be ok if your pond is shallower but it does depend on the pump and the spray pattern of the fountain.

There are many fountains with different spray patterns, you want one that exposes the most water droplets to the air if you want the best results for aeration.

To sum up

Fountains can aerate pond water, but they are not very good at preventing stratification as they can not recirculate water from the bottom of your pond.

They do add some aeration to the surface of the water but in general they are not suitable to aerate all of your pond, for that you need a dedicated aeration system.

One thing we would like to add is the use of your pond pump and filter system, your pond pump will constantly recirculate the water from the bottom of your pond which can help with aeration.