No matter what type of filters and how many filters you may have, routine maintenance should always be kept up. The The cleaner that you keep your filters, the cleaner and healthier your pond will be. A dirty neglected filter will only produce more waste returning to your pond. This article will look at the difference between mechanical and biological filtration, help you to understand how they work, and why they need regular maintenance. Also I’ll help you figure out, according to your own system, when to clean your filters.
There are two types of filters that we are going to discuss, mechanical and Biological. A mechanical filter is any filter that is designed to collect and remove solids out of the water. Solids are things such as sand, mud, fish waste, algae and leaves. This type of filter basically is what keeps your pond clean. A biological filter is a filter that is designed specifically to grow bacteria which does a chemical process that will naturally “balance” your pond. This process is called the nitrogen cycle. I have a video on my YouTube channel (Jersey Shore Pondscapes Videos) all about this as well as a video explaining in detail the different types of filtration. This bacteria is very important to build up in your pond and filter to keep the environment safe and healthy. Bacteria can grow on many different types of filter media. The more surface area a particular media has, the better it will be, as more bacteria will be able to attach to it.
The key to having a good functioning biological filter is to keep the surface area, where the bacteria is growing, clean. The bacteria needs a clean oxygen rich environment to thrive. A filter that is covered with sludge is not where you will be growing this beneficial bacteria. Any filter covered with sludge is mostly just polluting the pond even more. Filter pads are a great media to use for mechanical filters. They can provide a good surface area for bacteria to grow if kept clean. And they can be used in layers.
Bead filters are good for biological filtration, however the type of media (beads) used in them can vary as far as their effectiveness. There are many companies that design and manufacture bead filters. Each company designs their filters to be used with different types of media. Some media is larger like bio-balls. They are great for bacteria growth, but I find them not to be as good for mechanical filtration. Some filters come with small cylinder-like beads. These seem to provide the best of both worlds, lots of surface area and the ability to collect waste. A bead filter that is not backwashed on a regular basis to keep the beads clean will eventually clog up with sludge. This sludge will kill the bacteria in the filter and you will no longer have a biological filter.
There are many different kinds of pond filters for sale, and for the most part, all can do a bit of both mechanical and biological filtration. Some filters may be a bit better at one thing than the other. But again to sum everything up, the cleaner that you keep your filters, the cleaner the pond will stay and the better the biological filtration will be.
How often should your pond filters be cleaned? There are a number of variables here, so we will look a few different things to consider. First, the size of the pond in relation to the size of the filters and the waterflow (pump) that is passing through it. The size of the pump and the size of the filter is crucial to how well the filter can function. Being able to turn over a large volume of water through your filter is key. Passing your entire ponds water volume through the filters as often as possible is a good thing. However, passing a large volume of water through a small filter is not very effective as the water does not have much time to be filtered properly. Small filters will collect debris and clog faster than larger filters, thus requiring cleanings more often.
There is no such thing as “over filtering” your pond. The bigger the filters, and the more water that you can effectively pass through it, the cleaner your pond will be. Just for arguments sake, a pond filter that holds 100 gallons of water, on a 500 gallon pond will need to be cleaned a lot less than the same filter on a 2,500 gallon pond. Never skimp on the size of filter that you choose for your pond.
Another thing to consider is that the more dirty your filters becomes, the harder it will be to clean. So, not allowing those filters to get really packed with sludge makes your job easier too. Try to get yourself on a schedule for routine maintenance according to your own observations. I have maintenance plans with many of my clients, and I go once a month to clean my gravity fed filter systems. At that interval, my job is fairly simple, and the ponds are kept very clean. However, I have clients that will call me every few months, and when I go there the filters are usually a mess. This not only takes more time to clean, but the job is very dirty, messy and smelly.
Bead filters need to be backwashed on a regular basis. Keep in mind that these filters can clog and if they do, they will not function at all. Not only will the filter not work, they may even stop the waterflow back to your pond thus eliminating an oxygen source in your pond such as a waterfall. This can cause many if not all of your fish to die, especially in the summer when the water temperature is very warm. Some pond pumps used for bead filters are very efficient when it comes to energy consumption, but they are not high pressure pumps capable of thoroughly turning over all the media in the bead filters if it gets really clogged and packed with sludge. So keeping up with your backwashes regularly becomes very important to not allow an abundance of sludge to build up in the filter. This also keeps your biological bacteria happy and healthy in the tank as well, which results in good biological filtration.
The question that I get a lot is: Does cleaning your filters a lot “wash away” all of your bacteria? That is always a concern. In a bead filter as well as in other filters that use filter pads, the bacteria can physically attach itself to the media. This makes it harder to wash it away, however, I’m sure some can be lost in the process of cleaning. However, I clean all of my filters very well, and I have never had any problems with a rise in ammonia levels from the disruption of biological filtration when cleaning filters. I also truly believe that the majority of bacteria is not only in your filters, but in the entire pond system itself. It’s on your liner and any rock in the pond itself. So cleaning your filters has no effect on this.
Another concern in cleaning your filters and killing the bacteria by using city (chlorinated) water. This too makes sense in theory, but again in practical everyday experience, I have never had any problems with my pond’s natural balance after cleaning the filters. So in real life day to day use, I have never had any issues with any of this. I would say that if you have city water, and you are very concerned about using the city water to clean your filters, then try to use your pond water to clean things if possible.
One suggestion that works extremely well for me is to have a gravity fed filter or some sort of settlement filter in place before a bead filter. This collects all the waste and dirty garbage out of the water first before the pump sends the water into a bead filter. By doing this, the bead filters remain so much cleaner and much more effective biologically. They will then work at their most optimum level.
To quickly sum things up, understanding your own pond, and how your filters actually work is a great step toward your ponds success. Be observant of how your filters are working. Smaller filters may need more frequent cleanings, while larger filters may function longer between cleanings, but will be a bigger job when cleanings are required. Don’t let the filters get too dirty. The cleaner the filters, the cleaner the pond. And it’s easier to clean “cleaner” filters than really dirty disgusting ones. Keep up a regular maintenance schedule and don’t let things get out of control. Too many problems can arise from a neglected pond.
Leave a Reply