How to Choose Pond Filters

This article discusses submersible pond filters, external pond filters, pond skimmer filters, and waterfall filters for ponds.

 


 

Submersible Pond Filters

Submersible-Pond-Filters

Submersible pond filters are just like they sound: they are made to sit inside the pond and hook up to the intake, or suction, side of a pump.
These types of pond filters are excellent for use in formal ponds where hiding an external filter will not work and for preformed ponds and smaller ponds made with EPDM pond liner. Submersible filters often offer mechanical and/or biological filtration and can be purchased by themselves or as a submersible filter kit. Many submersible pond filter kits come with fountain heads and a diverter valve to run a separate water feature such as a pond spitter or fountain. Submersible pond filters can be added during the construction phase of the pond or easily at anytime the pond is complete. Many strides have been made with submersible pond filters. Now, submersible pond filters can be purchased with or without an ultraviolet clarifier (UV or UVC), too. Ultraviolet clarifiers are discussed further down this page.


 

External Pond Filters

Pressurized-Pond-Filters

Gravity Pond Filters

External pond filters come in two forms: gravity pond filters and pressurized pond filters.  Gravity pond filters sit outside the pond for easy access, easy maintenance, and keep the pond aesthetically appealing because they do not sit inside the pond. These types of pond filters can be purchased with our without a UV and can be relatively inexpensive when compared to pressurized pond filters.

 

Pressure (Pressurized) Pond Filters

 

Over the past 10 years, pressurized pond filters have become one of the most common types of pond filters for hobbyists. The ease of adding them to any pond, diversity with regards to location around the pond, and the unsurpassed clarity they provide is hard to beat by any other pond filter. These types of filters can be found all over amazon.com, Home Depot, and throughout independent stores across the country. Most of them backwash, they can be purchased with our without a UV, and they can be located anywhere outside the pond. Even better, the water coming out of the filter can be taken up to a waterfall. The main differences between pressure filters now days are availability of replacement parts and easy of backwash, and effectiveness of backwash. Many filters found at big box stores do not have available parts such as lid rings, replacement foam, and replacement o-rings. Many main stream filters like Laguna Pressure Flo filters are cumbersome and labor intensive to backwash. Some of the pad-less filters like TetraPond and Pondmaster pressure filters are not effective at polishing pond water and are ineffective unless the pumps powering the filters are very powerful.

 

So, what’s a “good” pressure filter for ponds?

In our opinion, PondMax is an excellent pressure filter that solves all of these problems. Parts are readily available, the backwash feature is easy to perform, Pond-Max-Pressure-Filterand they polish pond water. We have installed several of these in the St. Louis area and customers are happy with the performance and clear water provided by PondMax pond filters. What’s more, they have a high flow rate. Most other pressurized pond filters are limited by there flow rates which means that hobbyists required a pump for the pond filter and a pump for the waterfall. Most other pond filters are limited to half of their capacity with regards to flow rate. What does this mean? This means that if a pond filter is rated for 1,000 gallons, the maximum flow rate is 500 gallons per hour. PondMax stepped up to the plate and designed a filter that can handle a pond pump equal to the capacity of the pond filter. For example, the PondMax 3600 pond filter can handle 3600 gallons per hour. Even better, PondMax filters with the UV option have larger UV clarifiers. The PondMax 7200 pressure filter comes with a 55 watt UV!

 


 

Pond Skimmer Filters and Biological Waterfall Filters

 

Pond Skimmer Filters

 

 

Pond-Skimmers

Pond Skimmer Filters come in a wide array of sizes and have a multitude of features and benefits. There are pond skimmers for preformed ponds, pond skimmers that provide sole pond filtration, pond skimmers that accept UV lights, and pond skimmers for large koi pond applications.

Pond Skimmers, along with pond pumps, can be the heart of the garden pond. When installed, pond skimmer filters are the entrance to the filter system for pond water. Most pond skimmers will remove 80-90% of debris from the water surface before it has a chance to collect on the bottom of the pond. It is safe to say that pond skimmer filters serve many purposes: they house the pond pump making it easily accessible, they mechanically filter pond water before it gets to the pond pump therefore serving as a pre-filter, and they keep the pond pump out of the pond for a more aesthetic appearance.

Pond Skimmers are a diverse piece of equipment in that there are many accessories available for pond skimmers. Auto-fill valves, UV lights, and bottom drains are components that can be added to pond skimmers to lessen maintenance requirements of any pond. Higher end pond skimmers come with fake rock lids.

One key downside to most pond skimmers is that they cannot easily be added to an existing pond. Most, if not all, pond skimmer filters are designed to be buried in the ground next to the pond and fastened to the pond liner. A hole is cut inside the pond skimmer face plate to allow pond water to enter the pond skimmer. Adding a pond skimmer filter to an existing pond can be done, but, sometimes there can be a lot of involved labor.

Biological Waterfall Filters

Waterfall-Filter

Biological waterfall filters are an excellent choice for most koi ponds. There are many different brands on the market. For the most part, biological waterfall filters operate the same way in that water enters the bottom of the unit, collects, and travels through mechanical and biological filter media. Mechanical filter media is typically a filter pad or filter foam and biological media is typically landscape lava rock, ceramic rings, biological balls (bio-balls), filter floss, or bio-blox. Lava rock used to be the standard for biological pond filter media but the other choices have surpassed it in popularity.

Waterfall filters are the starting point of a waterfall. Although waterfall filters can be added anytime a waterfall is added to the pond, they are typically used in new pond construction because that is when most waterfalls are constructed.

Waterfall filters serve more that the important task of filtering a pond. Those of us that have rebuilt our waterfalls several times know that it can be tough to build a natural looking waterfall by taking a hose and lying in on rock and then covering it with rock. Waterfall filters take the water from the hose and spread it out to a desired width. They have a lip, or weir, that then delivers anywhere from a 12″ – 4′ wide sheet of water that can be diverted over rocks making a cascading effect or a sheet of water that falls straight into the pond.

In some cases, we may be adding a waterfall and do not need the filter, building a pond-less, pond-free, or “water-less” waterfall and want to use a waterfall spillway. This component is just like a waterfall filter minus the “filter part”.