Koi Pond Filters

What are Koi pond filters?

Koi pond filters are large filters specially designed for, you guessed it, Koi ponds. Koi ponds require a big filtration system that can keep up with the huge amount of waste that Koi fish produce. There are several different types of Koi pond filters, but they all provide a substantial amount of mechanical filtration and biological filtration.

How do Koi pond filters work?

Just like other pond filters, Koi pond filters work by filtering fish waste, debris, and other decomposing matter from your water using a process that involves both mechanical and biological filtration. First, waste is trapped by large amounts of mechanical and biological filter media. It’s then broken down by colonies of beneficial bacteria that convert toxic compounds, like ammonia and nitrite, into less harmful substances, like nitrate.

Unlike other pond filters, however, Koi pond filters typically have rotating, perforated drums that separate out large waste solids from pond water before it comes into contact with mechanical and biological filter media. These drums are kept clean by a spray bar/jet that blasts away any trapped waste solids. While they do help clean your water, a drum on its own won’t filter your Koi pond.

Another way in which Koi pond filters differ from regular pond filters is that they often keep specialised filter media, like K+ media, in constant suspension. This increases the frequency of water-media interactions, boosting the filter’s filtration capacity and keeping your pond clear. Again, this is great for Koi ponds full of messy Koi fish.

What are the different types of Koi pond filters?

There are several different types of Koi pond filters, but they all fall into two broad categories: gravity-fed Koi pond filters and pump-fed Koi pond filters.

The former are the most popular choice amongst Koi keepers. These filtration systems are fed by a bottom drain that needs to be installed under a pond area in a concrete base during construction. They rely on the force of gravity to move water and waste solids through this bottom drain and into a large filter unit.

The latter, on the other hand, rely on a pond pump to function properly. This can be an internal or external pump. These types of Koi pond filters aren’t quite as popular, but they work great in more natural-looking Koi ponds that haven’t been built with a concrete base and lots of intricate underground plumbing.

What are the benefits of Koi pond filters?

They may be beautiful fish, but Koi fish make one hell of a mess. Any excess waste produced by your Koi fish can very quickly pollute your water and, if left unchecked, cause deadly ammonia spikes. Koi pond filters are specially designed to process such large amounts of waste, and it’s for this reason that they’re the number one choice for Koi keepers who keep very expensive Koi fish. By keeping water immaculate, Koi pond filters also create the kind of healthy environment that’s conducive to rapid growth. For those keeping Koi, a large, beautiful fish is their pride and joy and something they can show off at Koi clubs and Koi shows.

When partnered with a quality UV light, a Koi pond filter can eliminate any dangerous pathogens, viruses, and bacteria that may harm your Koi fish. A UV light will also stop algal blooms in their tracks, ensuring your Koi pond isn’t taken over by unsightly green water. A lot of Koi pond filters come with UV lighting built in, like Evolution Aqua’s EazyPod Complete Automatic, but for those that don’t you can pick up an external UV clarifier that can be easily plumbed into your filtration system.

Another benefit of Koi pond filters over regular pond filters is that they can handle larger waste solids, thanks to their rotating perforated drums. These drums can be quite high-tech, with sensors triggering automatic cleaning cycles that keep them clean and clear of debris. This is great for Koi keepers who like to spend more time looking at their Koi fish than mucking out their filter.

Can Koi pond filters be used with other pond fish?

Yes, Koi pond filters can be used with Koi fish and many other popular types of pond fish, including goldfish, golden orfe, sterlet and sturgeon! Their biggest selling point is the fact that they can handle large amounts of fish waste, so they can be realistically used on any kind of heavily stocked garden pond, including special ponds like ornamental ponds full of colourful fish and vibrant aquatic plants. A quality rubber liner works great in these kinds of Koi ponds and serves as a fantastic foundation for a thriving, underwater ecosystem.

What size Koi pond filter do I need for my pond?

The answer to this question varies depending on a number of different factors. The first and most important factor is the volume of your garden pond – a Koi pond filter needs to be able to support the total volume of your pond, and then some. It’s always a good idea to opt for a filter that’s ‘too big’ rather than too small. If your filter system can’t handle the waste produced by your Koi fish, then they’ll struggle to grow and, over time, could develop some serious health problems. If you want to see your Koi grow big and strong, provide them with a big and effective filter system!

Another factor to consider is the type of Koi pond filter you’re planning to get. A gravity-fed Koi pond filter will require the construction of a bottom drain underneath your garden pond, while a pump-fed Koi pond filter will require a pond pump with a suitable flow rate and a max head height that's higher than the water level of your garden pond. Make sure you take these factors, particularly water level, into account before you purchase your Koi pond filter, as they’ll almost certainly dictate what model is most suitable for your pond.

What pond pump do I need for a Koi pond filter?

There are many different types of pond pumps out there, but the best for supplying Koi pond filters with a consistent supply of water are solids-handling pond pumps. These pond pumps are great at dealing with waste solids and can be easily cleaned thanks to their detachable strainer cages. We stock a wide range of solids-handling pond pumps, all available in different sizes to suit different sized Koi ponds.