Greenwater
Unlike lakes and rivers, ornamental garden ponds are generally of small size with limited depth. Therefore they can warm up more quickly than natural bodies of water; they also have greater sunlight penetration and a higher concentration of nutrients. These conditions stimulate the growth of algae, which cause greenwater problems. These conditions can be reduced by maximising pond volume, minimising stocking levels, placement of pond away from direct sunlight, or blocking sunlight using canopies or pergolas, not overfeeding fish, and using correct food ie wheatgerm during cold periods. The best way of preventing greenwater after taking all these considerations into account will be to utilise the correctly rated pump, filter and UVC. Pollution Caused by Fish Waste
Compared with natural ponds, garden ponds are usually heavily stocked with fish, which are fed more than they would normally find to eat in their natural habitat. Fish produce waste in proportion to the amount of food eaten. This waste is both solid and dissolved; this pollution is increased by the decomposition of plants and uneaten food. If these waste products are not removed they will eventually have a detrimental effect on your fish. Filtration is the key here, your filter should be large enough to cope with the demand placed upon it, if you wish to have large stocking levels, and you are intending to feed large amounts of high protein food in order to grow your fish to impressive sizes, then purchase a large efficient filter that can cope with these demands. Closely monitor your fishes behaviour, watch for anything unusual, this will be a sign that things are not as they should be, follow the pond feeding guidelines on this website, and remove any uneaten food or decomposing plant matter. 

Herons
Herons are the number one enemy of fish ponds. Besides catching and eating healthy fish, they injure others which die later. They are most troublesome in spring when they have young to feed, not in winter. They are no longer fooled by fake “decoy” herons. Deter them by putting a trip-wire around the pond or using an electric heron alert, or cover the pond with a net. Herons are less of a problem in towns or where a pond is close to tall fences, a shed or a greenhouse, as they need a long, shallow flight path before landing. 

Lack of Oxygen
Both green water and pollution can reduce the level of oxygen in pondwater. However, relatively high concentrations of oxygen are necessary to support healthy fish. The introduction of air into pondwater i.e. aeration, raises and stabilises the level of oxygen in the water. In addition the turbulence created by aeration will remove toxic gases. During the summer months when water temperatures rise lack of oxygen can become a problem, suspect this if you see your fish gasping at the surface. 

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ICH – White spot disease. Any parasitic infection is usually easy to cure if treated quickly with an effective dose of copper. If the dosage is too low, not all parasites are killed and re-infection results. If treatment is delayed, the parasites may become so numerous that they choke the gills and the fish suffocates or the fish becomes so weak it cannot recover. Treatment should continue for at least 4 days and a good rule of thumb is to treat the system every day until no sign of infection is visible, then treat one more day.
Signs of a parasite infestation are:
1. Visible spots, usually white. 2. Rapid or heavy breathing. Some parasites will attack the gills before any can be seen on the fins or body, and the fish may die from suffocation. 3. Scratching. If a fish constantly rubs against objects in the system and looks like he is trying to dislodge something, he is probably trying to rub something off and it is probably parasitic.

OODINIUM: This is actually a form of algae parasitic on fishes.
ANCHOR WORMS: These are easily visible and look like little sticks about 1/4″ long protruding from the body or fins. They are firmly attached and when pulled out may hold onto a piece of flesh.
FISH LICE: Are crustacean parasites with similar treatment as per anchor worms. They are about one quarter inch flattened discs with rasping mouth parts and hook-armored legs capable of damaging fins and skin.
LYMPHOCYSTIS: This is a virus that lives off of impurities in the water while attached to a fish. It does not live off the fish like ICH, but may kill indirectly by interfering with gill movement, swimming ability, or eating.
BACTERIA: Bacteria grow erratically and are often white or milky in appearance. A bacteria infection may be localized or may be evident on several areas of the fish. Bacteria infections are likely to be found in or around open sores or any area where the fish has lost it’s protective slime coating.
FUNGUS: Fungus spreads evenly, starting from a central point and growing in an outward pattern. Several areas may grow outward until they overlap and give the appearance of a bacteria infection. Fungus is white with a velvety or even hairy appearance. It is most likely to be found on the mouth, eyes, or tips of the fins.
POPEYE: This is a symptom, not a disease caused by a specific organsim. It is manifested by swelling behind the eye(s), or in the eye(s). The swelling may be caused by many factors but is most commonly caused by bacteria.
SWIM BLADDER DISEASE: The swim bladder is the organ which allows a fish to stay at any level in the water column without sinking or floating. The swim bladder may fail from damage by bacteria, parasites, genetic faults, or blows and/or bruises. When the swim bladder fails to function the fish loses it’s ability to swim normally and may swim sideways or even upside down.
DROPSY: Dropsy is a name given to any disease that causes a fish to swell so much that the scales no longer lay flat against the body of the fish. By looking down on a fish you can easily spot a case of dropsy.
SUFFOCATION: Rapid breathing or gulping near the top of the tank may mean a fish is not getting enough oxygen. This may be caused by:
1. No air circulation. 2. Temperature is too high. 3. The water surface is covered. 4. Parasites. 5. Overmedication burning gills, rupturing blood cells, causing too much mucus production.
BRAIN DAMAGE: Fish may show any unusual symptoms. This should be only offered as a diagnosis after all other possibilities have been ruled out. Erratic, jerky swimming or spinning are common signs of brain damage. Brain damage can be caused by parasites, bruising (concussion), high or low temperatures, or toxins.
TOXINS: Symptoms look the same as brain damage, but all or most of the fish in the system are affected at once. Spinning is the most frequent sign of a toxin.

OPEN SORES: These can be caused by:
1. PH that is too high or low. 2. Scraping on rocks or other objects. 3. Bites. 4. Parasites. 5. Internal infections reaching the outside. 6. Net damage during handling.

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Choosing the right type of pond for your own needs is the important first step. If you have a patio, your pond could be the focal point or it could be the centre feature of your landscaped lawn. It could also brighten a gloomy or neglected corner of your garden.
If you are interested in natural water garden you could create an almost totally natural pond, rich in native plants and a haven for all types of aquatic life. But remember such a pond would have a natural appearance and typically is not suited for ornamental fish because of the lack of proper filtration and it’s vulnerability to predators such as herons.
Another area of importance will be to decide whether you wish to keep beautiful plants and common ornamental fish in your pond or whether you are considering the possibility of a beautiful Koi pond. Because the site and construction for both ponds are very different you will be much more successful with your pond if you commit to a type of pond before you begin excavation.
The shape of your pond takes on two different styles. An informal pond has no straight edges and no symmetrical shape and may be designed to blend in with the contours of your garden landscape. Alternatively, a formal pond does have a regular shape and can be raised above the ground using brickwork to draw the eye to its symmetry.
Both types of pond are ideal for keeping aquatic plants and pond fish. A waterfall and a fountain or other moving water feature would usually compliment such pools.
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No matter what size you plan your pond to be, you will always wish you had made it larger. A pond 100 sq ft of surface area or larger provides an ideal amount of surface area for many varieties of aquatic plants and fish. This is not to say however that a smaller pond or a container garden cannot be enjoyable or interesting. The minimum depth should be 18 inches for ponds with plants and ornamental fish that are not Koi. However, if you are in a colder climate or are keeping only Koi your depths should be 3 ft or deeper. The proper depth will enable fish to survive the winter more easily and keep them cool in the summer months. A shelf of 12-18 inches wide and about 9-12 inches below the surface can be created for the placement of marginal plants and some other potted aquatic plants.
Once you have decided on the type of pond you would enjoy, it’s time to decide where to locate your pond. Locating a pond where there is too much sunlight should be avoided. Sunlight promotes the growth of algae and may cause the temperature of the water to rise dramatically during warmer weather, decreasing oxygen levels. To avoid this problem, position your pond where it will receive some shade, especially during the afternoon when the sun is the strongest. 5-6 hours of direct sunlight is ideal for most ponds with plants and ponds that are less than 18 inches in depth.
Beware of siting your pond beneath trees or near their roots to avoid leaves falling into the pond and potential root damage to the liner. As well as being unsightly, rotting vegetation in the water may adversely effect the quality of the water, which could cause harm to the fish. Another important consideration will be to site your pond close enough to an electricity source so you can incorporate a pump, filtration or lighting.

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LINERS
This can be either a rigid pre-formed pond or a flexible sheet liner. Both are easy to install and extremely durable. A pre-formed pond has the advantage of ready made planting shelves and areas for placing submersible pumps though a flexible liner allows you more creativity and a more individual design. Pre-formed ponds tend to be limited in size, when choosing a liner purchase a good quality preferably butyl liner with a 20 year plus guarantee, protect the underside of the liner by removing sharp rocks, and placing a thick layer of soft sand beneath the liner.

PUMPS
A pump is essential for circulating water through filtration systems. Pumps are also used for creating moving water displays such as waterfalls or fountains which, as well as being attractive features, will help to maintain oxygen levels during warm weather. Your pump should be able to pump at least half of the pond’s water volume per hour. There are a wide range of pumps on the market, bear in mind the pump will be running 24 hrs a day, so check out the pumps wattage, low wattage=low running costs, If you choose a solids handling pump you,ll have less maintenance, and no prefilters to clean, they are also good at removing debris from the pond bottom, to the filter were it can be removed.

FILTERS
Your filter keeps your pond water clear and healthy, they will use both mechanical and biological filtration to achieve this. Biological filtration utilises bacteria on the pond filter media to break down fish waste and organic matter. Mechanical filtration captures particles in a physical filter for removal during filter cleaning. A good pond filter will achieve both. Your garden pond filter should filter half the pond volume every hour at a minimum. Garden ponds that are exposed to the sun for more than 6 hours a day, or have Koi, should have a slightly larger filter to cope with this extra demand.UVC
An Ultra-Violet Clarifier is highly effective in keeping your pond free of water-borne algae which will make the pond water green, free-floating single celled algae cause green water in ponds. This algae is too small to catch even with an effective mechanical pond filter. UVCs expose the algae particles to enough UV light so that they clump together (flocculate). These larger particles can then be easily filtered out as they pass through the pond filter. LIGHTING
Lighting can really add a creative dimension to your pond at night. Lighting can be inserted into the pond, behind a waterfall, in a fountain, above the water, and even placed around the perimeter of the pond. Being able to see your pond at night can add a warm, relaxed mood or feeling to your garden. Pond lights are simple to install and will enable you to create magical effects at night time.

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Although is may seem obvious, aquatic plants are different to land based plants, because they have evolved to live in wet even submerged conditions. There are three principle groups of aquatic plants, all with specific needs:

Marginal or Bog plants – These are essentially the plants that stick up above the surface of the water and provide height to the pond. They can be planted into waterlogged ground or more commonly into plastic planting baskets, which are then placed into the water.
Planting Depth: 6 – 8 inches Care: Plant into planting baskets using aquatic compost, when the plant starts to die back in the autumn / fall, cut back the plant to ensure that the decaying plant material does not pollute the water. Feed once a season with an aquatic root fertiliser. Cultivation: Generally these plants can be cultivated by division in the spring, although because of the huge number of plants in this section it’s best to consult your nursery.

Hardy Examples: Water Iris, Pickeral Rush, Arrowhead,
Tender Examples: Papyrus, Umbrella plant, Water Cannas

Floating Plants – These floating plants have extensive root systems that dangle into the water from the surface, these root systems provide ideal spawning areas for fish like goldfish. They often reproduce by budding and as such can be very invasive.

Planting Depth: Allow to float unplanted on the surface

Care: They only care required is for tender variety if they are needed the following season. Take a strong plant in the early autumn and keep in pond water in a well lit frost free greenhouse. Periodically replace the water with fresh water. Stratiodes (the water soldier) sinks to the bottom of the pond in the winter and rises again in the spring.

Cultivation: Because these plants bud so easily, they can be cultivated by cutting the offspring away from the parent to produce a new plant.

Hardy examples: Water Soldier
Tender Examples: Water Hyacinth, Water Lettuce
Oxygenators – These are plants that are not very visable, as they are present under the water. But they can fulfil a useful role in the pond. They absorb nutrients, and can help to reduce the growth of algae in the pond. Calling them oxygenators can be a misnomer as although they produce oxygen during the day, they absorb it again at night. Oxygenation is best achieved using a pond pump.
Planting Depth: up to 18″

Care: These plants are usually purchased in clumps unpotted, and they do best when they are potted into planting containers with aquatic compost and dressed with pea gravel. Depending on the size of the container you should get 3 – 6 bunches per pot. You should have one bunch for every 2sq feet of pond surface.

Cultivation: When the plant becomes too big, simply cut a length off and plant up into a fresh container.
Examples: Anacharis, hornwort, cabomba.

Deep Water Plants – These plants have leaves that float on the surface and roots that are firmly placed in containers on the bottom of the pond. Water lilies are generally the best known aquatic plant. They are available in an enormous assortment of varieties and colours. Other plants like lilies are available.
Planting Depth: Variable up to 3′

Care: These plants should be in water that is at a depth specific to the variety in question. They should be planted in a generously sized container rich in nutrients, the compost should be covered with Pea Gravel and larger stones. If this does not prevent your fish from digging up the compost in their quest for food, then try enclosing the whole container with an old pair of nylons. These plants need regular feeding if they are to flower prolifically throughout the whole season. Dead leaves and flowers should be removed or else they will rot and pollute the water.

Cultivation: The lilies can be propagated by cutting sections from the rhizome, and planting in fresh compost . This should be done when the plant is entering the growing phase, not at the end of the season.
Examples: Many varieties of hardy, tropical, and night blooming lily, also water hawthorn, water fringe, water snowflake, and water poppy.

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For many people keeping fish is the main reason for having a pond. There is something intangible yet amazing about seeing fish in a pond, it will give the pond a magnetic draw, and they will become a source of constant pleasure for many years.

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Family Name: Cyprinidae (carps and minnows)
Length: Max 30.5cm (12″)
Weight: up to 0.9kg (2lb)
Identification: (Asiatic form) greenish when young changing to golden red as an adult, body shape variable, head scaleless, no barbels.
Habitat: Densely weeded lowland rivers, lakes, and ponds.
Breeding: Eggs laid on water plants in June and July, they take 7 -9 days to hatch, the young fish stay attached to the plants.

Note: Goldfish are the most common pondfish. Goldfish are inexpensive and fast growing. They are available in a variety of patterns and body shapes. Goldfish need a pond that has a minimum depth of 18″ but a pond closer to 2′6″ is more acceptable. However the more unusual varieties are less hardy than the true goldfish

Koi Carp (Cyprinus carpio)

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Family Name: Cyprinidae (carps and minnows)
Length: Max 150cm (4′ 11″)
Weight: up to 36kg (80lb) usually less
Identification: Scaleless head, body can be scaled or unscaled depending on the variety, as can colour , mouth toothless and has two barbels at each side.
Habitat: Large lakes and major rivers in slow flowing lowland areas
Breeding: Late spring in shallow sun warmed areas over dense vegetation. The eggs are attached to the plants.

Note: Koi are the most rewarding of pond fish. They are available in a bewildering selection of varieties. Don’t be put off by the Japanese names of the fish or by the high prices that they can fetch. If you see a fish you like in a pattern you like at a price you can afford – buy it. The most important thing is the health of the fish, a £2000 fish can die as easily as a £2 fish. That aside, Koi can grow to 3′ if conditions allow, they are fast growers and can consume a lot of food. They are avid rooters in pots and as a result can make the water dirty if an effective filter is not installed. The depth of the pond should be 3′ minimum

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One of the biggest problems in the Autumn and Winter is when leaves begin to fall from the trees above. If these leaves get in the pond and decay it will throw off the ecological balance of the pond. Remove by using a net to skim the leaves off the surface of the pond. FISH

As the water temperature falls we should be feeding our fish less as their metabolism slows down. After the water temperature drops you should decrease the amount of food given and feed only once a day. Once the temperature drops below 10 degrees C you should stop feeding altogether. Cold-water fish such as Goldfish and Koi cannot digest food properly below these temperatures. They will happily munch on algae and other natural foods if the water does warm up occasionally.

Do not allow your pond to completely freeze over, make sure you have a small area free from ice, as organics decompose in the pond they can produce toxic gases that can become trapped in the pond if it is covered by ice for more than a few days. Do not break the ice as the shock waves created can damage or kill your fish. Defrost a small area using warm water.

PLANTS

As plants are starting to die back, any dead and dying leaves should be removed,
place plants deep enough in the pond to keep the roots from freezing.

PUMPS & FILTERS

It is advantageous to keep your pump and filter running through the winter. The bacteria in your biological filter will not be active at low temperatures but it will remain alive as long as you keep it supplied with oxygenated water. When spring arrives and the water temperatures begin to rise the bacteria can start to work immediately keeping the water quality healthy for your fish and helping to control the algae. Should you choose to run your filter through the winter it is a good idea to minimize the water circulation.

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The following subjects are extensive, we will provide only basic advice on these pages:

Aquaria

Your fish will react to the conditions you provide for them, Your fish will thrive and provide you with full colour and rapid growth, if you give them enough room and feed them a good varied but balanced diet. For this reason buy an aquarium that offers volume and a large surface area, if your buying a smaller aquarium then reduce your stocking levels and buy smaller species! I own a Juwel Rio 400, the Juwel range offer cleverly designed beautifull aquaria and stands, that would compliment any room. If your considering a Juwel aquarium use the link on our links page to visit the Juwel site.

Filtration

One of the most important parts of your set up will be your filter, the filter will contain media, offering a large surface area to allow a colony of bacteria to grow, by passing water through this media any harmfull ammonia and nitrite in your water will be removed, providing healthy clear water for your fish community. I would strongly recommend encorporating more than one filter system in your tank, I would definitely advise backing your internal filtration up with an external system, or running two internal systems alongside each other!

Internal systems

One of the best systems is the undergravel filter, water is drawn down through your aquarium substrate and up an uplift tube using a powerhead or an air pump, this system utilises the whole of your substrate as the filter media allowing a substantial bacteria colony to develop, it also has little impact on the interia of your aquarium, all you see is the uplift tube which can easily be hidden with some tank décor. Another benefit of this system is any small particles or debris in your aquarium will be drawn down onto the substrate surface which will improve the water clarity.

Internal cannister type filters are similar to undergravels, they contain their own media inside the body of the filter and propel water through it using an impellor, they are normally positioned onto the side or back glass, with their outlet an inch or so below the surface of the water, this is advantageous as it provides surface ripples, increasing surface area and allowing more O2 to enter the water. I would recommend a “fluval” internal if considering this option.

External systems

The main advantage of an external is that they do not reduce the space available to your fish inside your aquaria, and you can carry out cleaning / maintenance on them without disruption to your tank, you will however need to consider routes for piping in and out of your aquaria.
I run a large Fluval external on my tank and I have run the pipes through the wall, the filter is situated in a cupboard on the other side, everyones situation is different you will need to consider the best option for yourself.

Other Systems

As you advance and become more confident and knowledgeable, you may wish to consider a centralised system running a number of tanks, or a specialised sytem such as a trickle filter.

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Heaters
Tropical fish require a temperature between approx. 20-30oC (68-86oF), with many species being kept at a ‘middle value’ of 24-25oC (75-77oF). Maintaining a stable temperature (and more importantly avoiding rapid changes) is vital to avoid stressing fish. The temperature of a tropical aquarium would normally be maintained using a combined heater/thermstat, placed inside the tank. These are available in a number of standard wattages between 25 watt and 300 watt. Some hobbyists will recommend, buying two heaters rather than one ie, instead of one 300 watt heater, use two 150 watt heaters, this is in case a heater sticks in the on position, it will have less of a heating effect on the tank. I would recommend buying one good quality heater such as a visitherm, these are extremely reliable and very rarely, do they give any problems, I would also recommend buying a thermometer to check water temperature, the ones that stick onto the outside glass are fine, check water temperature daily. Buy a heater with the smallest wattage rating for your size of tank, an increase in temperature has little impact on a fishes health, but a sudden fall in water temperature can cause harm. The table below gives examples of recommended heater wattages for various tank sizes. The modern combined heater-stats use very reliable thermocouples to maintain a stable temperature.

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Lighting

The lighting used in an aquarium is governed to a large extent by whether the tank is to contain live plants. If the tank will not contain plants (or only plastic plants) then the light need only provide a means to view the fish. The choice of lighting is then only governed by choosing a light which enhances the colours of fish. There are many different types of light tube available with varying spectrums, some give a strong blue light some give more of a yellow light. A light with more blue in its spectrum will bring out the blue colours in your fish, a light with more yellow in its spectrum will bring out the yellow colours in your fish. Think about the dominent colours in your fish selection and pick a light tube which will make the most of your fishes colours.

Planted tanks need more light than fish only tanks, and the type of lighting becomes more important. The light requirement of different plant species varies somewhat, but generally the light will need to be at least double that recommended for a fish only tank. A number of manufacturers produce fluorescent tubes designed to provide maximum plant growth. These include Arcadia’s Freshwater tube, Interpet’s Triton tube and Hagen’s Floraglo and Powerglo.
For heavily planted tanks, some may opt for metal halide or mercury vapour lights, which are normally suspended above an open-top tank. These are able to punch light deeper than fluorescent tubing and are therefore useful for tanks 24″ or more high. It should be remembered that when higher intensity lighting is employed to boost plant growth, it will be necessary to balance this with an adequate amount of nutrients and CO2.

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Pond filters
Decomposition of fish waste and plant debris releases toxins into ponds and depletes oxygen levels in the water. Simple ponds with few or no fish should not require filters. However, they are essential for stocked ponds where imbalances in the pond’s ecosystem are more likely to occur.
Mechanical filters
Mechanical filters simply remove solids from the pond by straining water through gravel, brushes or foam filters. They can be fitted directly onto a submerged pump and are suitable for small ponds with only a moderate fish population. Regular cleaning is normally required to keep them working properly (about once a week in the height of summer) though self-cleaning models are also available. The filter is effective immediately it is switched on, unlike the biological types described below.
Combined filters
Combined filters that use mechanical, biological and even ultraviolet (UV) means are more suitable for larger ponds with large populations of fish. Most of these combined filters are pump-fed and have a gravity outlet, and so are positioned higher than the water return point. More complex pressure-fed models can be part-buried. Combined filters can be placed after specially designed water pumps which can handle solids.
Biological filters
Biological filtration relies on naturally occurring bacteria that colonise a specially designed filter medium with a large surface area. The bacteria convert ammonia, which is toxic to fish, and other nitrogen-based compounds into nitrates. These are then utilised by pond plants, thus removing nitrogen from the water. Biological systems are essential for ponds with substantial fish populations (especially koi, which produce 40% more waste than goldfish). Unless bacterial supplements are used, the bacterial population takes six weeks to build up. If the filter is switched off for more than 24 hours the bacteria die and a further six weeks is required to rebuild the population. Biological filters only require cleaning at the end of the season. If cleaning is essential during summer, use pond water, as the chlorine in tap water kills bacteria.
Ultraviolet lamps
Ultraviolet clarifiers are placed at the front of the biological filter system. They act by killing green algae and make it flocculate (clump together), easing mechanical filtration. However, they do not remove nutrients from the water. Pond water is exposed to radiation from a UV lamp held inside a quartz tube. There are lamps of different wattage for various pond sizes; most require replacement every six months or so.
Pond size
Having determined the correct filter type for a pond, calculate the size needed. Mechanical filter sizes are easy to relate to water volume. Multiply the pond’s average length X average width X average depth (in metres or feet to get cubic metres or feet). Multiply this figure by 1,000 to get the volume in litres. When calculating pond dimensions in feet, convert the cubic feet measurement to gallons by multiplying by 6.23.
More notes
Additional factors affect the system. A major cause of failure is when fish populations and feeding regimes are not taken into account. Water surface area, pond depth and exposure to sunlight also affect the size of filter required. Speak to specialist suppliers and, if in doubt, go for a larger rather than smaller size, aiming to circulate all the pond water through the filter every two to three hours.
Always consult a qualified electrician before installing a filter system.

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Gases such as methane and hydrogen sulphide that result from the decomposition of decaying plant material are poisonous to fish if levels build up. This occurs in winter if the pond freezes over, trapping gases under the surface.

Never smash the ice as the shock waves can kill the fish. Instead install a heater before the winter, so it can be switched on when a frost is expected, to melt a hole in the ice. Alternatively stand a pan of hot water on the surface to melt a hole.

Expanding ice can damage a pond by putting excessive amounts of pressure on the walls of the pond. A float made from polystyrene or an inflatable ball, absorbs some of this pressure. After removing the float it is possible to siphon out some of the water to create an air pocket below the ice. 

Running a fountain can prevent the water freezing in an area large enough to allow gases to escape. If a pump is left in over winter it is worth running it on a weekly basis to keep it operating efficiently.

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