Pond Talk

Pond Advice For Small And Large Ponds

do it yourself pond filter

Do Homemade Pond Filters Really Work?

Pond Accessories, Small Ponds

One of the most popularly searched on pond topics today is for plans or designs on diy pond filters. Homemade pond filters offer a potential cost savings over commercially made filters but a question that many people wonder about is are they any good? Do they really work all that well?

The short answer to this question is that yes, in many cases, diy pond filter designs can and do work quite well. However there are some variables that really need to be explored in a bit more detail to get a clear picture of what may work best for your pond.

Commercial pond filters are offered in quite a few configurations. You’ll find these in the form of pressurized bead filters (most expensive) down to a very simple biological filter, and most anything in between. A popular trend today is the combination of a biofilter and a uv light all encased in one single unit. For very small ponds, mechanical filters that simply filter sediments out of the water are very common and inexpensive.

Homemade Pond Filters Use Biological Filtration

For the purposes of comparison it’s important to realize that when we talk about a homemade pond filter and the commercial one’s, we’re specifically talking about biological filters. Regardless of the manufacturer, meaning you or someone else, all of these filters use a form of beneficial bacteria, which is housed in various kinds of media (we’ll talk about this more in a moment) and it’s these good working bugs that do most of the clean up work.

When a person is comparing a diy pond filter such as the Skippy design, or something like a 55 gallon barrel filter, vs. a waterfall filter, or a box type filter, these are all very similar in the processes they use to clean the pond water. The container or shell of them may look quite a bit different but the processes inside are virtually the same.

Biological Pond Filters And Media

Upon looking in any typical biofilter you may or may not find several prefilters which are pads of various densities that will catch some of the larger pieces of debris that will flow through the pond. After this stage, you’ll then discover the water flowing into a biological chamber which holds some type of media material that provides a home to the beneficial bacteria. Good examples of this would be sponge like pads, plastic coiling strands, small tubes with ridges on them, among other things. All of these provide a place where bacteria can set up shop, build up, and be somewhat protected from the water flow.

Beneficial bacteria will naturally break down any organic elements in the water and it’s one of the most powerful, natural ways that a pond owner can keep a pond in better shape. A typical homemade filter will often fill up from the bottom of the chamber. At the very bottom is a settling basin or area for non-organic particles to drop into. Things like sand, small rocks, and non-decomposing debris ends up here while other material that can be broken down will eventually decompose with the help of the bacteria. As the water rises in the filter it’s pushed through the bio chamber area, filtered and cleaned, and then it exits somewhere near the top. It can flow directly back into the pond at this point.

Sounds a lot like a typical waterfall biofilter doesn’t it?

This is why we say that some very good homemade filters will do just as good a job as many commercial versions. There are many similarities between them. What’s most important for a biofilter to work well isn’t really the shape of the design but how it’s managed by the pond owner. For the best performance you ideally want the full gallon volume of the pond to pass through the filtration system about once per hour if possible. This flow rate can vary a bit of course but ideally you want quite a few passes through the filter in a 24 hour period.

Tips For The Best Pond Filter Performance

It’s important to always remember what the real power of a biofilter is, and that’s the bacteria that’s inside it. If this get’s depleted or low due to something like a random chemical treatment, or perhaps the pond has been shut down for awhile for repairs, then some degree of priming or adding bacteria in the water will be important to make sure you have a lively colony working within the biofilter. Adding bacteria to the water from time to time is always a good idea to make sure the bacterial density is in great shape.

Unlike a pressurized filter, most homemade pond filters don’t have any way to backwash or clean out the insides of the filter. However this may not be necessary or advised once everything is set up and running well. One mistake many new pond owners make is to keep cleaning out the entire biofilter on a weekly basis. The fact is, the system is designed to operate without much cleaning if the bacteria is doing it’s job. There is evidence that many of these filters could actually work continuously for several years of continuous use without cleaning. It’s important to remember though that it can take something like six to eight weeks for everything to build up to the point where the filter is functioning at full capacity. In the early weeks it’s critical to try to remain patient despite the fact that your water may be emerald green. Eventually, it will usually clear up on it’s own.

Comparing Costs Of Filters

DIY projects are obviously very popular simply because there is the perception that they may save a lot of money over simply purchasing something off the shelf. I use the word “perception” intentionally because there have been many occasions when a do-it-yourself effort ends up costing more money in the long run. Pond filters are no exception to this so it’s important to do your homework before you proceed with any project.

  1. Be sure to get a solid, proven pond filter plan in place.  (you’ll find many online)
  2. The plans should have a detailed list of parts and ideally sources for those as well.  Add up the costs and don’t just assume you will be saving money!
  3. Get a very clear idea of the filtration needs of your pond such as the full gallon volume and the potential fish loading that you may one day have to deal with.
  4. Find and use a good quality beneficial bacteria product that’s appropriate for the season and temperature.  Supplement with these as needed, such as following any shutdowns of the pond.
  5. Avoid routine cleaning of the filter (and particularly the biological chamber) and remain patient in the early weeks of setting a new filter up.

Commercial pond filter designs will likely continue to get more and more complicated and along with this, one would expect improved and more efficient performance.  Like everything else in the pond care industry, new technology will continue to advance the hobby forward.  Nevertheless, there are times when the tried, true, and simple systems will win out and be a great option for many people.  Creative minds are always coming up with great diy projects that work very well.  You can be assured that homemade pond filters are on that list and are providing some great results for many pond owners.

Do It Yourself (DIY) Pond Filters – Our Favorite Designs

Pond Accessories, Small Ponds

Of all the pond devices that you’ll see used in a small pond, few have ever been reinvented or replicated as much as a pond filter in the diy realm. DIY of course stands for do-it-yourself and the relatively simple design of most biological pond filters easily lend themselves to someone who wants to build one from scratch.

The purpose of any pond filter is to help remove physical and elemental contaminants from the water. For instance pieces of leaf debris or single cell algae particles would be considered physical in nature. Elemental substances by our definition would include things like ammonia or nitrites that are created from the breakdown of fish waste. The reduction and elimination of these is very important because they are toxic to fish.

Pond filters in a broad sense, come in two varieties. Some may be physical filters only. Like an oil filter in your car, for example, these are simply designed to take out some of the larger particles of stuff that are floating in the water. This debris get’s caught in the mesh or foam, and filtered water is allowed to pass through. Many very small ponds, and those without fish, may use these and they can be helpful at keeping a pond cleaner.

Pond Bio-filters And How They Work

A more powerful, and we think, useful pond filter is the biological filter. This particular filter may or may not have a mechanical pre-filter included in it, but within a bio-filter is material that will grab some of the organic debris that passes through it. The important part though is what’s also inside the filter. The “biological” component is actually beneficial bacteria and this is the real cleaning tool of the device.

As material gets trapped, and this is specifically relating to organic material, this will be broken down, or in a sense, eaten by the bacteria. These good bugs will also convert ammonia and nitrites into harmless nitrates which is very important work for fish ponds.

Of course there are many commercial varieties of pond filters available and many of them are very good. Some, such as the fully enclosed bead filters can be quite expensive which is one of the reasons why many people want to save money and try to do something for themselves.

Here’s a video showing a very good, basic design for a gravity fed pond filter, with an equally good explanation of how it works.  This one uses a plastic storage tub.

DIY Barrel Pond Filters

The barrel filter uses a 55 gallon barrel. Often these are blue in color and can be found quite easily if you know where to look. Many factories and companies use these to hold liquids. Ideally if you know someplace that uses these for food grade products rather than chemicals of some kind you’d be better off. What’s nice about the barrels are their holding capacity and they can be found inexpensively. In some cases you might find them for free but you can also get them on ebay for around $20.

Barrels make good filters because of their round shape. This provide a very nice vortex or circular motion of the water internally which can help add a bit of oxygen to the water prior to it rising into the bio-chamber. Multiple barrels can be daisy chained together to help provide filtration to bigger ponds.

drum or barrel pond filterPvc pipe is installed internally within the barrel, along with some screen, filter foam or screen for prefiltering, and some type of media that can provide a home to the bacteria. The photograph included here show’s a nicely designed barrel filter in use in a fish holding tank. Water can be pushed into the filter by use of a submerged or external pump, and discharge takes place through an outlet pipe near the top of the barrel.

To get more details on this filter design this is one of the best videos we’ve found online.  It discusses how to properly daisy-chain barrels together for higher capacity filtration for larger ponds.

Looking to build just a single barrel pond filter?  Here’s one that’s well designed with a good presentation on how to put it together.

The Skippy Filter

Update:  The Skippy Filter website that was maintained for many years is no longer available. Nevertheless, this filter has remained quite popular and you may still use some of the widely available components to build your own filter.  I decided to leave the Skippy in the article as it might provide some inspiration for the reader.

Perhaps the most popular DIY pond filter online is called the Skippy filter and this uses a stock tank for the filter body rather than a box or barrel. Stock tanks also provide some circulatory motion of the water much like barrels and they will also have water enter at the bottom of the tank and this will rise up through the filter media, which is made up of numerous brillo like pads that not only filter the water but they also provide home to the bacteria as well.

skippy filterOnce filtered, the clean water will exit near the top of the tank. In this way the Skippy filter can serve somewhat like a waterfall filter and it can be hidden behind rocks or plants.

Comparing the various designs you’ll find many similarities. Really the main difference for the Skippy is that it uses no pre-filters or pads, just the loose scratch pads, to filter the water.

One key point that you’ll read about concerning these bio-filters is that they generally don’t require too much cleaning, in fact as the Skippy information will note, you may not want to clean them at all. It’s important to note that both of these designs and really any bio-filter will need to be primed with beneficial bacteria and this is easy to do. Simply add your favorite blend to the pond water and it will circulate into the filter. This may need to be done from time to time to keep bacteria counts up, and it certainly should be done at every spring start up or following a period of downtime where water flow is not going through the filter.

What About The Filter Media?

Up to now we’ve talked a lot about what these diy pond filters look like…but in truth, the real workhorse in this operation is the filter media.  That material, be it foam pads, plastic balls or tubes, no matter the make, its purpose is to provide a sustainable home to beneficial microbes.

It’s the microbes that help to manage nutrients from fish waste or decomposing organic material.  They also serve as a natural pond cleaner and balancer, and that work will provide the pond owner with a better looking, and much healthier pond.

So is there one form of media more preferred than another?  Opinions vary because it seems, as in the case with the Skippy filter, many porous materials will work reasonably well.  Some of the top rated media to checkout however would be the K2 Biofilter Media, the Nezo Bio-ceramic blocks, or the Easy Pro Bio-Blo.

Do It Yourself Or Not – It’s OK

The most important thing to remember is that you don’t need any great construction skills to make a good, useful DIY pond filter. With the information resources provided here, you can experiment and learn and ultimately create the perfect filter for your pond.

If after viewing some of the videos you come to conclude that building your own  filter is more than you want to tackle, you can still find easy to assemble pond filter kits online.  Many are designed to make creating a waterfall or spillway quite easy and they work great as a gravity fed pond filter.