Pond pre-filters are usually encapsulated in a plastic case with some sort of foam rubber / filtration material surrounding it that filters out any debris before it enters your impeller and clogs up your pump. Pumps typically come equipped with a pre-filter when you purchase. Some pumps do require you buy it and install it separately. It is important for you to be cognizant of whether the pump comes with a pre-filter included prior to purchasing. Another variant to the pre-filter is called a pump sock. It's typically netting, usually lined with a foam material that slips over your pump. Pump socks are not ideal because the pump can suck the bottom of the sock into the impeller which causes havoc and more work than if you had no pre-filter period.

Pond filtration bio-filters are installed outside the pond with a UV light attached seems to offer the best of all worlds. This filters can be used for either commercial or personal use such as a hobby (Koi Pond applications). The neat things about bio-filters are that they keep blanket weed and / or string algae and most other common algae out of the pond. There are several brand offerings all of which provide for good operation. Bead type filters come in a canister full of beads that resemble a packed full jar of milk duds. The small "beads" function as surface growth sites for bacteria and to help keep your pond clear. UV lighting destroys bad bacteria and suspended algae. Cleaning is simple thru a back-wash effort via a turn of the handle with very little water loss in the process. One potential downside to a system like this is cost. In some large pond applications the system can easily exceed $5,000 USD.

Pond filtration biofilters are truly versatile whereby they can be installed in or out of the pond. There is also the option of having UV combined with the operation which only enhances it overall functioning. Bio-filters build up a colony of good bacteria that eat algae and develop your pond into a balanced ecosystem.Mechanical filters simply filter out suspended particulate matter from your pond. The mechanical filter requires monthly cleaning to wash out the debris it has removed. Mechanical filters are typically less expensive than bio-filters.For larger ponds we recommend a bio-filter housed outside the pond. Gravity feed provides for the water to be pumped into the filter which then drains out into your pond. Typically you will want to cover your system in some fashion (fake rock). By adding a dedicated pump for this filter you then have the option of creating a splendid waterfall for your pond which will generate some nice natural noise. Bio filters can be left alone and cleaned yearly unless you feed your fish or have Koi. It is always a good idea to introduce aeration and create movement for ponds and waterfalls.

It is possible to create your own pond filtration apparatus. You should use at least a 5 gallon nursery pot which can typically be bought at your local Lowes or Home Depot store. The filter you build will be a container of lava rocks or bio balls which will act as the filtration medium. It is important to know that the water must cover the filter while the pond pump will be kept at ground level. You must get the water into the top of the filter and pull it out of the bottom with a small pond pump. This can be accomplished with a simple tap that attaches to the intake of the pump. An alternative method is to put the lava rock (or bio balls) into a mesh sack; then put the pump at the bottom of your filter apparatus with the bag on top. It is important to make sure the entire system is full of water so the pump is primed and ready so when it is plugged in the system is fully functional.

If you have no live fish, plants or debris which can get caught in the pump then it is possible to have no pond filtration. Without a filter we do recommend aeration and movement for all ponds and waterfalls to keep the water vibrant.