Koi

Multichamber filters operate well in both gravity-fed and pump-fed ponds. Although they have a large footprint, they are cheap and durable. It is vital that you choose the right type of filter and filter media for your pond:
• Your filter system must have the ability to settle out solids, enough surface area to house biological filter media and be able to drain away any waste that collects in the unit
• Circular chambers give better settlement and cut down the chance of any dead spots
• All your filter chambers must have a drain so that waste can easily be flushed away
• If possible, the base of your filters should have a central drainage point with the sides sloping towards it to encourage optimum waste removal
• If you are unable to install a vortex then install suitable media in the first chamber to collect solids
• Three filter chambers is a good starting point – the first settles out solids and the next two are for biological filtration
• Pros: maintenance is relatively straightforward – all that is required is regular flushing of the waste valves, or standpipes, located on each chamber. Periodic backwashing of the media chambers can easily be done by opening the waste valve on that chamber and then powering pond water over the media to flush away any debris.

Although many Koi keepers still consider traditional methods of filtration, such as a settlement chamber followed by a multichambered unit, to be the best, there are other options open to you. Some of these can be used instead of these methods while others can be added to an existing system.

Bead filters
• Look like traditional sand filters
• Have a high-pressure blower for cleaning, which makes maintenance very easy compared to a standard sand filter
• Can be considered as either an addition to your pond or a replacement for the biological filtration stages of your existing system
• Contain thousands of beads with very high surface area
• Pros: small footprint and easy maintenance – simply move the multiport valve and it cleans itself in minutes
• Cons: don’t like blanketweed or large solids
 
Towers
• Either a single tower of media (such as a large-diameter pipe filled with a suitable media) or a number of trays housing the media through which water will pass through – the aim is to create a trickle of water over the media
• Are usually installed as the last stage of filtration before the water returns to the pond
• Pros: may reduce blanketweed and algae, can be home made very easily, very low maintenance
• Cons: lots of heat is lost as water trickles through the filter, must be placed above water level

Showers
• Tend to be stainless steel
• Consist of a number of trays which house media. Water showers down at speed to the levels below, which allows for both biological and mechanical filtration to take place
• Are usually installed as the last stage of filtration before the water returns to the pond
• Pros: new models are less obtrusive than the older versions, can be fed directly from a bottom drain with no settlement
• Cons: lots of heat is lost as water trickles through the filter, must be placed above water level

Fluid sand-bed filters
• A fluid sand filter is worth considering as an addition to your existing system.
• Consists of a cylinder which contains a small volume of occolatic sand
• Water is pumped underneath the sand at a controlled rate to ensure that the water doesn’t take the sand with it
• Pros: massive surface area in a very small space, relatively maintenance-free
• Cons: must be placed above water level, the sand would come out of suspension and compact very quickly if the pump stopped, killing much of the good beneficial bacteria
• The correct flow must be maintained at all times throughout the unit otherwise the sand will not be fluid enough, or it may end up in the pond

Sieve filters
• Inside the unit is a stainless-steel sieve, which can filter down to 100–300 microns or more. As water enters the unit it falls over the sieve, and this continual flow of water pushes the waste to the bottom of the stainless-steel sieve.
• Suitable for both pump-fed and gravity-fed ponds as the main means of mechanical filtration.
• A popular alternative to a vortex for waste settlement before the main filter unit.
• Work well with bead filters or other pump-fed filter systems due to the high amount of waste that they remove.
• Waste can be removed from the unit by opening a waste valve and flushing the unit through.
• Pros: very easy to maintain, smaller footprint compared to a similar-sized vortex, most sieve filters allow two bottom drains to be run into one unit
• Cons: too costly to be economical on small ponds

Eazy Pods
• These units combine both mechanical and biological filtration and are an ideal main filter for pump-fed or gravity-fed ponds up to 2,000 gallons, although they can also be used as an addition to your current setup
• Offer both mechanical and biological filtration
• Easy to maintain

Written by Keith Holmes