Do you need a pond filter, and if and so, which one? We show you your options in this easy to follow guide to pond filtration.

You need a pond filter in lodge to achieve one or both of the following things: Clean, clear water, or a salubrious environment for fish. Pond h2o often goes green, and the combination of a swimming pump, swimming filter and an ultraviolet clarifier tin foreclose the common trouble of green water.

Swimming fish also produce waste but are not equipped to live in their own waste product, so fish swimming filters can convert fish waste matter and prevent it from getting polluted. If you want articulate water and healthy fish, you need a filter.

Which box filter for my pond?

Box filters are unproblematic plastic boxes containing a multifariousness of mechanical and biological filter media. Water is pumped into the box by a pump situated in the swimming, and continued to the pump past pond hose.

Pond water is pumped into the top of the box and drips through filter media via gravity. Physical waste matter is trapped, typically in sponges, before passing through biological media containing beneficial bacteria, and returning to the pond.

Box filters are simple and constructive, and one containing mechanical and biological filtration media will be capable of supporting fish, breaking downward their waste product, and clearing the water of debris. A box filter won't forestall greenish water however unless it has a built-in ultra violet clarifier (UVC) or you lot fit a separate UVC to the pipework between the pump and the filter.

Why choose a box filter?

Box filters are suitable for all sizes of garden ponds, and are elementary to maintain, just by taking the chapeau off and squeezing the dirty sponges in old pond water. If they get very dirty most have a congenital in bypass, significant that water will still circulate, offering essential oxygen to pond fish.

They are a basic pond filter only its simple to add boosted biological media or chemical filter media like carbon or zeolite, and beneficial bacteria products can be dropped or poured into the media, getting to work direct abroad.

There are two small negatives with box fish pond filters - firstly they are large, so may be cruddy if situated at the poolside and non hidden, and secondly, as they piece of work via gravity, they need to be situated at the highest place in the system for water to return via gravity to the swimming.

This means that if yous accept a waterfall, the box filter must be placed at the acme of the waterfall, equally it can't exist placed poolside, and then water exit uphill to the height of the waterfall. H2o would overflowing the box. But if you don't have a waterfall, tin identify it well-nigh or next to the pond, and want a lot of filter for your money, box filters are an excellent option.

Which pressure filter for my swimming?

Pressurised swimming filters are cylindrical canisters with a tight plumbing equipment lid. Just similar box filters they contain biological and mechanical filter media, h2o is pumped to them by a pump in the pond, and models with built in UV are available to preclude green h2o.

But unlike box filters, water exits the filter at pressure, not by gravity. This ways that the filter tin can so be placed some distance from the pond or at the base of a waterfall, and an actress swimming hose tin can then take water upward to feed the waterfall.

Pressure filters tin even exist partially cached up to their lids, for the most discreet placement of any swimming filter. Its their compact size and numerous benefits that make pressurised pond filters the about popular filter systems for garden ponds.

How to make clean a pressurised pond filter

Pressure filters vary in their ease of cleaning. Basic models involve unsealing the hat, removing the sponges and squeezing them in sometime swimming h2o, merely like box filters. But advanced pressure filters enable sponge cleaning without getting your easily wet, and even flushing that muddied cleaning h2o to waste via a tertiary outlet.

Force per unit area filters can produce very clean, clear h2o as the water is forced through the media and tin can't bypass via an easier route, but they can cake if not cleaned regularly, and flow through the swimming will reduce. If you lot have a very large pond, or large Koi carp, you lot may also want to choose a different type of filter, which is capable of handling more solid and biological waste.

Which Koi filter for my pond?

Koi carp tin can grow very large, up to a metre in length, and with that comes lots of food and lots of waste. Koi ponds are typically designed with big fish and large amounts of waste in heed, and are deep, with aught to cause or collect waste in the swimming like pond plants. Koi may swallow plants also.

And dissimilar standard box and pressure filters, koi ponds are often run every bit gravity fed systems, with a lesser drain and surface skimmer congenital into the base and side of the pond, and so a large filter is placed next to the swimming, and pump and uvc are outside of the pond too.

With gravity fed pond filtration, h2o overflows from the pond down big, rigid pipework, drawing fish waste product with information technology. One time in the filter waste is physically removed first, then treated biologically by lots of biological filter media, before a powerful external pump sucks h2o from the filter, pumps it through a UVC, then returns it to a swimming.

Koi filters deal with so much muck and fish waste material that some don't utilize sponges at all, equally they would get dirty very rapidly. Instead, they trap or foreclose waste product from travelling further and allow flushing of that waste via drain valves, before the biological filter has to break it down.

Why choose a koi filter?

Standard box and force per unit area filters can be used for koi, but most experienced koi owners, with large fish and large ponds, choose gravity fed koi filtration systems. Koi filters tin can also exist pump fed in the standard way, with a pump in the pond, and hose connecting pump to filter.

But if you choose the gravity fed route the pond volition need to be designed and built differently from scratch, in club to install the bottom drain (which is fixed into concrete,) and the surface skimmer in the pond wall.

Which All-in-one swimming filter?

At the other cease of the scale, if you take a small swimming and desire clear, good for you h2o with the minimum of equipment, an all-in-i pond filter may exist what you lot need. All-in-one pond filters combine the pump, filter media and UVC in ane small unit.

Place the unit into the pond h2o and it will exercise everything that smaller ponds require. They also frequently come up with fountain attachments and hose tails to enable a small watercourse to be powered at the aforementioned time. They are minor, user-friendly and very cost-effective.

What are the limitations of All-In-One pond filters?

All-in-one pond filters are only designed for minor pond filtration however, and if used as the sole class of filtration in large fish ponds, they may fail to break down all the waste and go on the water clear, or they may clog upwards.

Merely go on them within their maximum water volume limitations and yous'll be fine. And with that filter media within the unit itself, you will need to remove the whole unit from the bottom of the pond each time in gild to make clean the media, which can mean cold, moisture hands in winter.

FAQs on pond filters

How do I calculate pond book?

Yous can calculate your pond volume in litres in the following fashion: Length ten width x depth in metres, x 1000.

So a ii.iv ten one.viii x 0.6m pond =two.592 cubic metres, x one thousand = 2592 litres. Circular the book upwardly to the nearest 500 litres and you'll need a filter and UVC for 3000 litres volume. For koi carp, pond keepers often double the filter capacity again, and so aim for a filter capable of filtering 6000 litres book, for the above pond with koi.

Can I over-filter a pond?

Ponds in full lord's day, or containing koi, may need extra help in order to maintain crystal clear water. There is no limit to the size of pond filter you put on your swimming, and the larger the filter and UVC, the better your water quality volition be.

When do I give the pond filter a boost with leaner?

All make new pond filters volition be effective at trapping waste, but not converting ammonia and nitrite from fish waste until they mature. Benign bacteria tin can also die off due to the use of medications, replacing old media with new, or ability cuts, so in all cases beneficial bacteria should be used to bring the biological filter to life.

I take a summit of the range filter merely my pond has blanketweed. Why?

No swimming filter and UVC volition prevent the growth of blanketweed, and it needs to be treated separately with dedicated blanketweed treatments. This is because it grows on the poolside and doesn't travel through the filter or UVC.

For more pond essentials, bank check out our range of pond liners and swimming pumps.