What Exactly Is Pond Filtration?

Pond Filtration Primer

Clear water is the goal. Now how do we achieve that?

Probably most realize that backyard ponds need filtration. Filtration comes in all sorts of forms however -- maybe not what you have pictured in your mind either!

Ancient pond filtration. No one wants to see this in the
bottom of their pond!

Submerged Filters
In the beginning... okay maybe not the beginning, but before modern day pond filtration was invented in the early 1990's, most pond filtration consisted of a pump in the pond bottom which drew the water through a container of lava rock also sitting in the pond bottom. This was somewhat effective, but unsightly and very high maintenance. This system was tweaked a bit to become the submerged filters that are still sold today -- a good percentage of new pond owners start this way, but it hasn't changed that much -- you can still see it in the pond bottom and it's still high maintenance. But for many, this is a low cost way to filter their pond and get started.

Today, modern filtration equipment is not
seen at all in or around the pond when
it is installed properly.

Modern Filtration
Today's modern day filtration consists of two components -- a biological waterfall and a skimmer. This system filters the pond exponentially better than the submerged filter and if installed properly is hidden, making the pond look much more natural.  The biological waterfall cleans and clarifies the water while the skimmer both protects the pump from debris and removes debris from the water. Read more about Biological Waterfalls here.

This spilling urn is both a filter and decorative!

External Filtration
Somewhere in between the submerged filter and the waterfall/skimmer combination lies the external filter. While the pump still sits in the pond bottom, the filter sits outside the pond making filter maintenance easier. These filters can be easily hidden or decorative such as the photo above. These filters are a great option for very small or hard-lined ponds.

There are other natural pond filters in the pond as well. 

There IS a creek in there! The plants are thriving!

If you look closely you can see the debris build-up.

Creeks and Streams
This spring we added a creek to our large pond in front of our shop. We added it simply as a debris filter. Because of the way the pond is constructed and the fact that our street floods terribly when it rains, all the debris from the parking lot ends up in the pond -- yeah, not a great situation. So we added this creek (and an accompanying skimmer) to remove the fine, excess debris. As the water flows through the rocks and gravel in the creek, it drops and collects in the gravel. You can see the build up. We simply use a pond vac and vac it out every so often. Works like a charm! Read more about the benefits of adding a creek here.

Rocks and Gravel in the Pond
What exactly is biological filtration? It's beneficial bacteria going to work breaking down and eating up all the excess nutrients in your pond that can feed algae. In order for the beneficial bacterial to do their job, they need a place to live -- like all the surfaces in your pond. If you add rocks and gravel to the pond, the surface area for bacteria to colonize will increase exponentially! One to two inches of river rock in the pond bottom is an awesome filter!

Aquatic Plants
Plants are natural filters all the way! They eat excess nutrients that build up in the pond. Not all plants are as good eaters as others, however. Although water lilies shade the water, they're not great nutrient eaters. For the best results, marginal plants put in areas where water flows through their roots will be the best at filtration. As well as eating nutrients, their roots will catch fine debris too. (Another reason to add a creek!)

Supplemental Beneficial Bacteria
In our backyards, we're trying to imitate Mother Nature. She has plenty of beneficial bacterial to keep natural bodies of water in balance. In our backyard ponds, we do things to upset that balance -- too many fish, fish food, inadequate plant quantities, etc. So it's important to supplement with BioClear and Clean (beneficial bacteria) to keep that balance by its consuming the excess nutrients.

All ponds are unique and require their own filtration solution to look their best and remain healthy. There are lots of easy ways to increase your pond's filtration or you can start with the easiest and lowest possible maintenance -- the biological waterfall and skimmer. Need some advice? All of us at Cool Ponds are happy to help!


Popular Posts