STOCKING THE POND WITH SUITABLE FISH: Ensure their future home is perfect for them

Now you are the lucky owner of a water garden or backyard pond, you may have always intended that this would be a home for fish. But what fish? 

Apart from ordinary Goldfish, fish that are suitable for average pools of any size include: Red Comets (Sarasas), Shubunkins, Golden Orfe, Tench and Rudd. These will all happily live with one another. More ornamental cold water Goldfish such as fantails and bubble-eyes, find it difficult to compete with other types particularly in the colder months. It is probably best to 'over winter' them in an aquarium indoors if you want to keep them There are always exceptions to the rule and here in one of my first ponds, koi do live in a tolerable harmony with plantssafe and healthy.
Various forms of ‘Fantails’, being slower movers than many pond fish, would find it difficult to compete in winter 
All the above fish are quite content to share their lives with Koi Carp. However serious keepers of Koi Carp need to think in terms of a minimum depth of 3ft - preferably 5 to 6ft - with a proportionately large width and length.
Koi keepers very often have to think in terms of no plants or at least have them protected from the vandalism of the fish. Therefore because of the lack of the biological cycle in which plants form an essential link, and also because of the rapid metabolism of these potentially very large fish, a sophisticated filter system is essential in keeping Koi. They are not fish of extremely cold water and find our winters stressful to say the least. When fish are stressed, then they are open to disease and parasites, and since Koi are such expensive fish, the only way to keep them with confidence is to employ all the quirks of pool design and filter technology at your disposal. (See all the recent biofiltration articles)

But first, before you even think of introducing any fish to your pond.......

MATTERS TO BE ATTENDED TO: POINTS TO BE SURE OF 

1.Is it a stable environment you are introducing them to? Is the pond over 18ins (45cm) deep, with over 30sqft (2.8sqmtrs) surface area? This will ensure a fairly steady temperature change as the weather changes.
Goldfish are the hardiest pond fish available2. Late spring is the best time to introduce fish. When they have had time to build themselves up after the trials of a long hard winter. Avoid end of season 'bargains' at aquatic centres. If you are tempted after the beginning of September, quarantine the new arrivals over winter, on through the early part of the next spring, in a separate tank. This is because winter will hit them before they have had time to recover from the trauma of the move. Any latent sickness or parasites that they may be carrying might take the opportunity to flair up and pass on to the rest of the fish population.
3. Related to the above: do not move the fish if the water temperature or the temperature outside is very high or very low. Water temperature of 50F - 10c is too low. An outside temperature of 30c - 85F is too high. Remember, it is radical change that affects the fish more than anything, be it temperature or water quality (see below).
4. The pH value of the water is particularly important too - buy a cheap testing kit to test it.
If there has been a lot of building work around the pool or there has been a lot of limestone used in the pool construction, lime may be leeching into the pool water. If the water is under pH 8 that is generally tolerable, 7-8 is ideal. If it is getting on for pH 9, you have problems.
Either pump the water out and stabilise the areas leaching lime with Silglaze or adjust the pH balance with chemical adjusters, keeping a very regular check on it for several days afterwards.
5. If the water in the pool was mains tap water, has it ‘aged' sufficiently? This means leaving the water to stand for 3 days whilst the chlorines, minerals and heavy metals 'drop out'. If not, it can be treated with 'Pool Conditioner', which will have achieved the same end after 2-3hrs. Overdose to be on the safe side. Many of these conditioners contain special colloids that help repair any damage to the fish's mucous layer, their only protection from disease and parasites. This can be so easily damaged in transit or reduced by the stress of the transition.
6. Is there a complete range plants growing in the pool and established as a welcoming party? Oxygenating plants are particularly important. Put in 1 bunch for every 2sqft of surface area.
7. Large pipes, slabs raised up of the pool bottom with bricks and purpose built 'fish hides' are an excellent idea for shy fresh arrivals. They are also fairly effective protection against the heron.

GENERAL RULES FOR CHOOSING FISH

1. Whatever the temptation, there is one golden rule for a stable healthy environment. Keep the fish population to LESS THAN 2" of fish for every square foot of surface area. This translates to 42cm to 1sqmtr.
An amendment to this, particularly in regards to Koi carp, would be to buy the fish with some regard to their future size and weight. It is true to a certain extent that many species of fish 'grow to the size of the pool', but this Ensure the fish are handled and packaged properly by the retailer. (see: Introducing your Fish to the Pond)brings the whole environment to the threshold of disaster in times when resources of oxygen and space are limited at certain times of year. Also this size of fish to pondl imiitation can be burst through by heavy feeding of the fish, which further stresses the environment the fish are in.

2. Regulate numbers on introduction. Introduce in 1's and 2's. Avoid adding more than 3 or 4 per season.
3. Get the fish from a reputable supplier near to home. The fish dont want to be travelling for hours in a car on a hot sultry day.
4. Observe how the fish are dispensed. They should be handled as if they were a Nitro-glycerine, touch sensitive bomb. They should be caught quickly and expertly. Admittedly the best ones are probably the liveliest and therefore the hardest to catch. It is therefore better to get your fish on a quiet day at the retailers, rather than when there is a fairground style hubbub and the fish are being chased around in a chaotic melee.
5. If there are any dead fish in the retailers tank then that is a bad sign. You can generally expect they are not the first of the day. It is usually the retailer's first job of the day to 'pick out the deads'. If there has been more 'deads' since then, or a dead fish is just floating in the tank from the night before whilst it slowly releases the pathogens that were its demise, suspect that there may be something potentially wrong with all the fish in the tank. If you were to choose a fish from this tank, take it to a new home and introduced it to a completely different environment, thus putting excessive stress on it, this will more than likely bring out the disorder in your newly adopted orphan.
6. Choose a fish with good colour that is lively and active. Small fish are proportionately much cheaper and settle into their new environment very quickly. They grow quicker in a new pond as well.
If you get a mixture of sizes you will find that the larger fish inhibit the growth of the smaller ones. This happens on a 'pecking order' level for the food supplies and by hormones released by the larger fish.
7. The fish you choose should be transported home in a large plastic bag. The depth of water should be enough to comfortably cover the fish when the bag is upright. The bag should then be pumped up with oxygen and tied off at the top with an elastic band. The bag can then be supported upright in a cardboard box.

A swarming school of shubunkinsCHOICE OF FISH TO SUIT THE ENVIRONMENT

GOLDFISH AND THEIR CLOSE RELATIVES

Goldfish are without doubt the hardiest and most suitable fish for any beginner's pond. They can withstand the rigours of any British winter. They are easy to see and come in a variety of colours Suitable pond fish for beginners in the UK: Top left: Goldfish. Top right: Sarassa Comet. Bottom left: Shubunkin. Bottom right: Golden Orferanging from white or silver through pink and orange, to bright reds with possibilities of blacks or browns.
They also come with a variety of lengths of fin and mixes of colours, which means they are ascribed other names such as Fantails, Sarassas, Wakins, Calicos, Comets and Shubunkins (London and Bristol types). They are all basically breeds of Goldfish (Carassius auratus) and as such are perfectly happy in each other's company. (However the very fancy 'Bubble Eyes', Black Moors, Lion Heads, Ryukins and Fringetails find it difficult to keep up on the feeding stakes. These are best kept in an indoor tank, especially in the winter.)

Being members of the larger Carp family (Cyprinidae), Goldfish are tolerant of most other fish. They are not disruptive and calmly go about their business. They are the fish we expect to see looking into an ornamental pool and so are in keeping with many typical styles, either formal or informal.

BUT WHAT OF THOSE OTHER TYPES WE SEE?

THE FORMIDABLE KOI

     One fish that is always easy to see and is
definitely prone to upsetting the balance in a pool is the Koi carp. Sometimes
referred to as ‘Living Jewels’, these fish epitomise the brightly coloured
elements of some of the Japanese Koi in colour and profusiongardening styles. Those of you eager to get
into the pastime of keeping Koi carp will not need me to extol the beauties of
these gems, but hopefully you will bear in mind the size these fish can grow to
(30ins), therefore you will stock the pool to suit this prospect. Allow
yourself 1 Koi for every 2sqmtrs of water surface and expect for 6-10ins (15
-25cm) growth per year.

     To make them feel really at home they will
need a depth of 3-4ft (1mtr -1.5mtrs) minimum and a filter system processing
the total volume of the pool every 2 hours.

     Despite their size, Koi are cuddly big
bears of the pond and are quite happy to share their space with any other
ornamental fish as long as it is large enough not to be mistaken for food.

     Some people are lucky and find that their
Koi will exist quite happily with lilies and oxygenators. Most people however
go through a rigmarole of trying to keep them out of the planting baskets with
heavy pebbles then wire mesh. But resort in the end to taking the plants out
and providing a mechanical means of oxygenation and engineering shade with
pergolas and netting over the pool. Koi are playful vandals and get bored very
easily.

They need to be fed the best quality food available
and the food appropriate for that season. This will not only help them but help
the filter and you keep on top of keeping the water clear.

GOLDEN ORFE

     The Golden Orfe is an essential fish, in
my mind, for the larger pool (growing to 18ins-2ft, 45-60cm). They are active
and need the space of at least 50sqft (15.5sqmtrs) to move around in. In a
group they will constantly shoal, Golden Orfe are recogniseable by theri giant crrot shapeproviding us with never-ending, smooth,
elegant movement, looking like a string of fast moving flexible carrots being
dragged through the water.

     Although very hardy, they are the first to
succumb to the effects of pollution, oxygen depletion or rapid temperature
change. You will help them through the winter by keeping water movement to a
minimum. Also be very careful with fish disease remedies and old-fashioned
algicides; read the information on the packaging very carefully and only dose
accordingly. These fish will be the first to benefit from the change in EU
regulations on algicides.

     Apart form this they are as easy to keep
as gold fish and can live for 10 to 20years (the larger the pond, the longer
they live). They dont have any bad habits either and love the company of other
species of fish, although in turn, they can be harassed to death by some
aggressive types.
Orfe love to shoal with their own kind

Fish that will find it difficult in a garden pond all year round
The Sterlet is carnivorous and loves deep cold water	Bubble eyes and lion heads are bred for indoor cold water tanks	Calicoes are like fantailed Subunkins and find it dificult to compete with bigger faster fish.