There are such a lot of filtering products on the market these days that it can be difficult to find the proper one for your pond. There are different methods used to filter the water. The term biological filtration refers back to the system which uses bacteria to get rid of biological waste products from your pool. Mechanical filtration is the removal of larger debris from the pond water. Chemical poisons are removed from the water using chemical filtration.
It is nice to know how the different systems work when you go buying a pool filter. A filter system that only cleans your pond using one of the methods mentioned above may not do everything you need. There are multiple different styles of filtration system that you should buy. The Nexus filtration system mechanically and biologically clean the water in your pond. They use either gravity or a pump to move water through the filters various chambers.
Water is first put thru a mechanical filter, then put through the biological filter, and then it is pumped back into the pool. With a vortex filter the water is revolved through a conical shape to remove solid matter. This is mechanical pond filtration. The quantity of mechanical filters that are needed will rely upon the size of the pond.
The water is sent thru a biological filter before it is going into the pond. Pressurised pond filters are usually smaller than some of the other types. The water is under pressure as it comes though the filter which causes waste to get caught in the filter much more effectively. This gives you much higher biological filtration than you would have with an unpressurized unit. Regardless of what sort of filtration system you have you will likely need a pump too. This will permit enough water flow thru the filter system so it can be effective . Learn more about chemical filtration here.