The Aquascape Ecosystem Pond

A naturally-balanced ecosystem pond is the key to a beautiful, enjoyable, and low-maintenance water gardening experience. At Aquascape, we’ve taken great pains to ensure our water features create a healthy and sustainable ecosystem that works with Mother Nature and not against her.

The Secret Recipe
The recipe for a naturally-balanced Aquascape ecosystem pond must include the following five ingredients, which will ensure minimal maintenance and maximum enjoyment for outdoor living.

Circulation
Since this construction is a self-contained system and is always re-circulating its water, any well-conceived water garden starts with a good circulation system. This system starts with a pump, which has sufficient power to handle the required load, but not so much as to render it inefficient. There’s a formula (see sidebar) that will help you accurately calculate this information. The pump must also be built with enough integrity to live up to a standard warranty of “one year of continuous use.” Aquascape warranties all of its pumps and we continuously perform field-testing to make sure we provide you with the best quality products on the market.

Our circulation system is rounded out with a strong yet flexible connector such as flexible PVC piping. The pump should be housed in a skimmer, which is designed to skim debris from the surface of the pond into a basket-like net which can be taken out, dumped, and easily placed back in the skimmer.

Filtration
Since we’re re-circulating water and providing a home for fish (one of the 5 key ingredients) the next consideration is the filtration system. Recognize that there are two kinds of filtration going on in an ecosystem pond - mechanical and biological. Mechanical filtration physically impedes debris, while biological filtration helps to break down the debris and to render it re-usable in the nitrogen cycle (which we’ll mention shortly). Aquascape provides a variety of mechanical skimmers suited to any size pond.

The Job of a Skimmer
The main function of mechanical filtration, or skimmer, is to remove debris before it sinks to the bottom of the pond and decays. The skimmer also houses and hides the pump and plumbing from view, as opposed to being placed directly in the pond where they become an eyesore. The skimmer won’t drain the pond if a possible leak occurs in either the plumbing or waterfalls.

There are two main types of skimmers: box skimmers and floating skimmers. Both types filter the water by removing floating debris and waste before it’s had a chance to fall to the bottom of the pond. The box skimmer is the predominant type of skimmer on the market today because it’s easy to maintain.

Box-style skimmers come with either vertical or horizontal filter mats. Horizontal mats prove to be the most effective, while providing the least amount of maintenance. In addition to frequent cleaning, vertical mats need to be constantly monitored to make sure there is enough water in the pump chamber for the pump to operate properly. An advantage of horizontal filter mats is that they lay flat so there is no sagging and they don’t lose their shape. They also never clog to the point of preventing water from passing through, so the pump chamber does not run dry. As water enters the skimmer, the large debris is removed and the water is then further filtered through the horizontal mat. The pond water then travels through the plumbing buried underground, up to the biological filter where it’s further treated before re-entering the pond.

On the biological side of filtration, including aerobic bacteria into the recipe will allow Mother Nature to efficiently break down biodegradable debris that finds its way to the bottom of the pond. Aquascape’s BioFalls® Filter are designed in a unique way to maintain an efficient nitrogen cycle which is key to a healthy, sustainable ecosystem. Without bacteria doing its job on behalf of Mother Nature, the muck is a monster!

Biological Filtration Goes to Work
The biological filter receives water that has already passed through the mechanical filter, or skimmer, typically placed on the opposite side of the pond. The water enters the biological filter via flexible pipe located near the base of the unit. The water then flows from the bottom to the top of the filter, traveling through filter media housed inside the unit. The filter media helps with the removal of fine to medium-sized particles. The larger debris was already removed by the skimmer.

As the biological filter fills, it will overflow and cascade over its waterfall lip, cascading down rocks that have been set to create a beautiful and preferably natural-looking waterfall. The waterfall creates aeration for the pond, assisting in the circulation and health of the water. If a slower, stream effect is preferred, the unit simply needs to be sunk lower into the ground.

Biological filters on the market today range in size and can filter ponds up to 10,000 gallons. For larger ponds, multiple biological filters can be incorporated into the design.

Mechanical and biological filtration are critical to processing the many types of nutrients found in a water garden system, including fish waste, uneaten fish food, leaves, and runoff from lawns to name a few. High levels of ammonia (a form of nitrogen) are highly toxic to fish and are a major contributor to prolific algae growth, and so they need to be carefully controlled. In water gardening, the primary nutrient that biological filtration utilizes and renders usable is nitrogen.

In biological filtration, nitrifying bacteria, known as facultative bacteria, absorb ammonia, and turn nitrites into nitrates, which are less dangerous. These bacteria require oxygen to live, so it’s important for the pond’s pump to run 24 hours a day, 7 days a week. If the pump isn’t running, the waterfalls aren’t flowing, and aeration is eliminated from the necessary equation to maintain an ecosystem pond. Keep in mind that if the pump shuts down, the bacteria will quickly use up all of the oxygen and die. This isn’t a good thing.

Nitrates are then removed from the pond by another biological filtration method known as de-nitrification. This process occurs only in anaerobic (without oxygen) areas of the pond. That’s why it’s not necessarily bad for some areas of the pond to experience minimal water flow (such as on the bottom of the pond, under an inch or so of gravel). The bacteria that live in this area of the pond turn nitrates into nitrogen gas, which is released into the atmosphere. Nitrates are also absorbed by aquatic plants and algae during their growth processes. A pond without aquatic plants will prove to be a maintenance nightmare.

For any biological filtration to work, there literally needs to be billions of bacteria working to purify the water. They prefer to anchor onto things, which is why surface area is so important. More surface area means more bacteria, and more bacteria means better biological filtration. Surface area is provided by filter media, rocks, and gravel. A pond with gravel on the bottom will contain more surface area for bacteria, as opposed to a pond with exposed liner on the bottom.

Rocks and Gravel
The third requirement for the naturally-balanced ecosystem pond recipe is rocks and gravel on the horizontal and vertical surfaces of the pond. The presence of rocks and gravel serve three valuable purposes. First, it holds the liner in place while protecting the rubber liner from the sun’s ultraviolet rays, which, if unimpeded, will cause it to deteriorate much faster than necessary. Second, rocks and gravel give the required aerobic bacteria a natural place to colonize. And third, rocks and gravel simply look natural in a way that a smooth surface never could.

Fish
The fourth requirement is fish, preferably koi or goldfish because they seem to be tailor-made for water gardens. They are colorful, user-friendly, and make great pets, but there’s more than meets the eye here. Fish are scavengers and they feed on various things in the pond including algae, mosquito larva, debris of various kinds, and aquatic plants. And after they eat, they produce waste, which falls to the bottom of the pond and is, in turn, broken down and recycled into the nitrogen cycle and used as nutrition by the aquatic plants in the pond. A pond without fish is unnatural, as well as aesthetically and practically incomplete.

Aquatic Plants
The fifth requirement is aquatic plants. The first reason to include them is, of course, aesthetic … they look and smell beautiful and natural in and around the pond. But on closer examination, they’re much more than just good-looking. They’re fish food and are consumers of pond nutrition and by virtue of competing for pond nutrition; aquatic plants are discouragers of algae. As a matter of fact, in order to minimize an algae bloom, there needs to be a sufficient amount of aquatic plants competing for the available nutrition, which effectively starves (discourages) the growth of algae in the pond.

By the way, these 5 key ingredients work synergistically, so eliminate any one at your own peril. So to summarize here, it’s kind of like the song where “the knee bone’s connected to the shin bone.” The various elements in the naturally-balanced ecosystem recipe are connected together in such a way that one is dependent on the other. Take one out and you’re asking for imbalance and all the problems that come along with it … complements of Mother Nature.

It’s important to remember to keep all the various parts to the puzzle in proportion as well. In other words, while it’s important to have fish, too many fish in a given pond will prove counterproductive. Rocks are necessary to make it work, but a layer of about an inch is just right, if you make it six or eight inches deep you’re asking for trouble too. Over-filtering, too much pump pressure, and over-planting of aquatic plants are all things that you should avoid. It’s like when the doctor says to take an aspirin – if you take a couple you’ll eliminate your headache, but if you take a couple dozen, you’ll cause a big one.

If you’re hiring someone to install your ecosystem pond, be sure to secure a Certified Aquascape Contractor. That way, you’ll know you’re getting a proper balance of circulation, filtration, fish, plants, and rocks and gravel. If you’re a do-it-yourselfer, you can locate an Aquascape retailer who will be able to answer your questions and provide quality water garden products.

The recipe for a beautiful, naturally-balanced, and easy-to-maintain water garden is really quite simple as long as you include all 5 ingredients.