Koi – The only magazine for practical Koi keeping advice

CROSS INFECTION
Cross infection occurs where two or more animals from different sources are put into contact with each other, allowing any infectious agents to be transmitted from one to the other.

ECTO-PARASITES
Ecto-parasites are parasites that live on the body surface of the fish, such as the skin, fins and gills. This is in contrast to endo-parasites which live inside the fish, in the gut, blood, or organs.

EGG FUNGUS
Egg fungus is a fungal growth on eggs that can be rampant and kill incubating eggs. It usually takes several days to take hold.

FLASHING
Flashing is the response seen on fish that are irritated by parasites, flicking and scratching against the pond edges and baskets to free them of their irritation.

FREE LIVING STAGE
Free living stage(s) refers to the stage(s) of a parasite that occur in the water, rather being attached to (or living within) the fish.

HAEMORRHAGING
Haemorrhaging is reddened areas or red streaks on the skin or internal organs, caused by leakage of blood vessels. It is often a sign of a bacterial or viral infection.

OPPORTUNISTIC PATHOGEN
An opportunistic pathogen is a disease causing organism (like bacteria) that will try to colonise a weakened fish given half a chance. Stressed or susceptible fish will be more open to infection.

PATHOGEN
A pathogen is an organism or substance that causes disease. In the case of Koi there are plenty of little parasites that like to take a grip, like fish leech and lice and anchor worm. There’s also a huge variety of bacteria, all of which must be accurately diagnosed before treatment.

POP-EYE
Pop-eye is a condition in which one or both eyes bulge out from their sockets. In the case of dropsy, both eyes are usually involved. The condition is also referred to as exophthalmia or exophthalmos.

SVC
SVC (spring viraemia of carp) is caused by a virus. As the name suggests, this disease tends to occur in the spring, when the water temperature remains below 15°C.

SYSTEMIC
Systemic means affecting the whole body. Systemic infections are sometimes life-threatening and can be difficult to treat.

TRICHODINA
Trichodina, chilodinella and whitespot are microscopic parasites that live on the exterior of fish. They cause irritation and can often cause fish to secrete excessive quantities of mucus.

WHITESPOT
Whitespot is a potentially lethal parasitic disease which manifests itself as thousands of tiny dots.

AIRSTONE
An airstone is a perforated rubber, sponge or ceramic ball, through which air is forced, creating a stream of bubbles.

BOTTOM DRAINS
Bottom drains are built into the base of a pond and shaped like a biscuit tin, with a 10in diameter and a 4in pipe outlet on the side. They have a dome cover to prevent fish swimming into them. The 4in pipe runs directly to the first chamber of the filter. Bottom drains remove all fish waste and debris that settles on the bottom of the pond.

BIOLOGICAL FILTER
A biological filter is a vital part of any pond system. This chamber (or chambers) follow the mechanical filter. A good, long-established biological filter should be home to a colony of aerobic bacteria that convert toxic ammonia to less harmful nitrates. This bacteria can be boosted with regular additions of polybac or ABA (ask your local Koi dealer).

EXTERNAL PUMP
An external pump is not designed to run under water, and requires air circulation for cooling.

FLOATING SKIMMERS
Floating skimmers are self contained units, powered by their own pumps. They are usually submersible and can be positioned for maximum effectiveness.

FLOW METER
A flow meter is used to determine the exact gallonage for treatments and medications. It should be used when a pond is first being filled.

G4
G4 is a polyurethane-based sealer for brick, concrete, cement, plaster and wood, which can be applied by brush or by roller.

MECHANICAL FILTER
After the water has passed through the vortex, it travels on to the mechanical filter. Brushes are used to trap any solids which may have escaped the vortex.

POWER SKIMMER
A power skimmer is used in conjunction with an external pump to remove floating debris. The moulded ABS box is installed behind the wall of the pond. The skimmer box has a floating gate which sits at water level. As the pump is turned on, the top layer of water is continually skimmed, removing all debris. Inside the box is a collection basket which needs regular emptying.

SAND FILTER
A sand filter is a totally sealed fibreglass spherical container into which water is pumped at high pressure through a bed of silica sand, to remove fine debris. It is most commonly added to Koi ponds as a last filter.

SETTLEMENT CHAMBER
A settlement chamber is the lower part of the filter, to which waste is channeled. The solid matter sinks to the bottom.

SUBMERSIBLE PUMP
A submersible pump is designed to run under water, generally relying on submersion for cooling.

UNIVERSAL HOSETAIL
A universal hosetail is a stepped adapter that makes it possible to accept pipe between 1.5cm and 3.5cm diameter.

UV UNIT
When an ultra violet clarifier (UV unit) is installed on the return of pond water, it will eliminate green water forever (no, really, it will!)

VEGETABLE FILTER
A vegetable filter containing plants like arrowheads, water lettuce and water hyacinth, will absorb harmful nitrates and phosphates from pond water.

VENTURI
A venturi injects air into the pond water. It is made from 1in pipework and has a restrictor inside and an air tube which extends above water level. Water is pumped through the venturi, and the restrictor forces air to be sucked in from the tube above water level and mixes with water inside the venturi to cause thousands of tiny bubbles that aerate the pond water. It’s used to improve the aeration in the pond and increase the oxygen level in the water.

VORTEX
Vortex: when this cone-shaped unit is installed, the pipework from the bottom drain is connected to it. When the valve is pulled, the water enters the chamber in a whirlpool action drawing heavy solids down in a gravity-fed, clockwise flow to the steeply-coned base of the vortex. By pulling the vortex valve, these solids are flushed to waste. The water exits the upper part of the chamber via a 6in pipe towards the next stage of filtration.

BROODSTOCK
Broodstock are those Koi used for spawning.

CULLING
Culling is the process of removing the Koi without potential and will occur two or three times during the first year. All remaining fry are worth growing on.

EPITHELIUM
The epithelium is the layer of cells that form the outer surface of the skin and gills.

FIN RAYS
Fin rays are bony filaments that support fin tissue. They can be seen within the tissue of all fins.

HAND-STRIPPING
Hand-stripping is a procedure by which the milt (sperm) and eggs are manually removed from the Koi rather than being shed naturally during spawning. Hand-stripping involves gently massaging the ventral parts of the fish to expel the eggs and sperm which are then mixed together in a container to facilitate fertilisation. Hand-stripping requires care and skill and can seriously damage adult Koi if performed incorrectly. Seek expert instruction before attempting this delicate procedure.

LATERAL LINE
The lateral line is a surface ridge which runs along each side of the Koi’s body. It has sensory function, notably vibration detection.

MUD POND
Mud pond is the popular term given to a natural pond (at least 100,000 gallons) excavated from the local ground. Usually clay and shingle based, they are used for growing on Koi at extremely low stocking rates. While a little natural food occurs in these ponds the Koi are fed mainly with sinking pellet food through the period from May to October. It is considered that the mineral qualities within the clay assist the development of the Koi.

OPERCULUM
The operculum is the flap covering a Koi’s gills.

OSMOREGULATORY
The osmoregulatory system of a Koi is the means by which it maintains a constant concentration of it’s tissue fluids. Osmoregulation is a complex process by which fish maintain a constant level of salts within their body fluids. Fish cannot function properly, and may die, if their body salts become too high or too low. Various organs are involved in osmoregulation, including the kidneys, gills, skin, and liver.

PEDUNCLE
The peduncle is the area between the dorsal and the tail fins.

SPIRULINA
Spirulina is an algae that is often added to Koi food to enhance the fishes colour. It can’t induce colours that aren’t already present.

ADSORPTION
Adsorption is the adherence of one substance to another, usually caused by magnetic polarisation.

ALKALINITY
Alkalinity refers to the sum total of substances in water, predominately carbonate and hydroxyl, which maintain the pH reading above 7.0.

AMMONIA
Ammonia is produced as a waste product by Koi and also generated from organic decy. If the ammonia level gets too high then it will kill your fish. Regularly monitor ammonia levels with test kits.

ANAEROBIC BACTERIA
Anaerobic bacteria function without the use of oxygen. Aerobic bacteria need oxygen to function.

BIOMASS
Biomass is a population of micro-organisms that break down waste and remove toxins.

DEHYDRATION
Dehydration is the removal of water from something, often from the cells of organisms.

ECOSYSTEM
Ecosystem refers to the natural interactions and food webs found in a pond that keep the surrounding environment in balance.

HORMONES
Hormones are chemical messengers in the body, which are released from certain organs and have specific target organs. Hormones function more slowly than nervous impulses, and the dose of hormones can be altered.

NITRIFICATION CYCLE
Nitrification cycle: here, a population of micro-organisms, known as the biomass, breaks down waste and removes toxins. The biomass should be regarded as a living organism that requires a) an adequate food source b) sufficient oxygen c) temperatures between 10°C – 40°C. Filter media should offer plenty of surface area and allow easy access of water through all parts of the filter. Disruptive chemicals should be avoided if at all possible.

NITRIFYING BACTERIA
Nitrifying bacteria break down fish waste from ammonia nitrite to nitrate.

NITROSOMONAS BACTERIA
Nitrosomonas bacteria are oxygen-loving (aerobic) bacteria that oxidise total ammonia (NH3 +NH4) into Nitrite (NO2). It is important for a biological filter to be kept clean and well oxygenated, so that these bacteria thrive.

OSMOSIS
Osmosis is the chemical term for the travelling of a substance through a membrane from a weaker to a more concentrated solution.

OXIDISATION
Oxidisation is the chemical addition of oxygen to a substance.

PH BUFFERING
A material with pH buffering qualities contains calcium carbonate, which will mop up the acid-causing hydrogen ions in the pond water, thereby preventing the PH level from dropping.

PHEROMONES
Pheromones are hormones released by the body into the environment, and in fish can trigger fright responses or even reproduction.

POIKILOTHERMIC
Poikilothermic means that internal blood temperature is dependant on external temperature. This affects the Koi’s whole system, effecting changes in energy levels and metabolism.

STRATIFICATION
Stratification is when a boundary between two layers of water exists as a result of differences in density or temperature. Stratification impedes the mixing of the two separate water layers.