There are many different types of Pond Filters such as submersible, pressurized, gravity fed, waterfall, and some even come with a UV Clarifier inside.
A submersible filter is used as a pre filter for a pumps intake yet also will remove waste from the water. These filters are used mostly in smaller ponds since they will need to be retrieved for cleaning.
Pressurized Filter is a canister that water is pumped into from a pump and pushed out its outlet up to a waterfall or back in the pond. These filters are installed outside of the pond and can be buried up to the lid. They usually have a backwash system for less maintenance and can come with a UV inside of the filter.
A gravity fed filter will either be next to the pond or top of the waterfall. Water will go into the filter box and as water rises inside it will come through the outlets located near the bottom of the filter. These filters can come with UV Clarifier or without one.
Waterfall Filters is a type of gravity fed filter however the water will rise and go over a spillway. Needless to say a waterfall filter is most commonly used for your waterfall and camouflaged by rocks and landscaping.
You will want to match your pond filtration system with the amount of water you have in your pond, the amount of pond fish you expect to have and if it will be Koi or Goldfish or even both. It will also depend on if your pond is getting full sun, partial or shade. When you have Koi or large amount of fish and or sun, you will want a big enough filter.
Many of the fish filters will have mechanical and biological filtration.
Mechanical will physically remove debris and waste from the pond by filtration materials, such as foam pads, that trap suspended particles. Other filters that do not have a foam pad will develop a slime coating on the media and then particles will adhere to it.
A bio filter will have some kind of bio media for growing bacteria. This will aid in removing the harmful effects of organic waste and ammonia.
A UV Pond Filter with will have the advantage of clumping suspended algae and trapping it in your filter keeping your water clear from green water. If you have an excessive amount of algae you will want to clean or back wash your filter more often.
Matching up your filter with the correct pond pump is very important. Most pond filters can only handle so much water flow through them to work correctly.
By not under sizing your filter you will have a clearer and healthier pond.
