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Stocking your fish pond - Best fish and tips

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After all of the planning and building of your fish pond it is very exciting to begin to think about adding the fish, sadly even at this stage you will need to be patient to ensure that any species of fish that you do add have the best possible start in your pond and will live long and healthy lives. There are many species of fish that you can choose from, some are more suited to larger fish ponds while others reach a full adult size that is fine for medium sized ponds, hopefully this article will enlighten you as to which fish are suitable for your fish pond and show you some of the popular choices available.

There are certain rules that must be followed before you are ready to add your fish so informing you of these first will give you a good start when it comes to the actual stocking. Firstly once the fish pond is built and filled with water it is not ready for the fish, the water needs to age and the filters need to be capable of dealing with any fish waste produced in the water i.e. the filters need to have cycled by the use of bacterial starter cultures so that the colonies of beneficial bacteria are large enough to convert the ammonia and nitrites into nitrates, if not the fish will be living in toxic water and they will soon develop diseases from the stress caused by poor water quality. You can cycle the fish pond by adding a couple of fish but this practice is dying out rapidly as more humane ways of preparing the filters are more readily available.

One common question is how many fish can be added to the fish pond?

Quite simply the equation for this is based on the surface area of the fish pond. The fish are dependant on the oxygen in the water, smaller surface areas absorb less oxygen so less fish can be added, many novice pond keepers can make the mistake of judging the stocking levels by the total water volume, larger volumes can slightly increase the stocking levels but by following the guideline using the surface area you are sure to provide enough space and free oxygen for each fish that you add.

To work out the surface area simply multiply the length of the fish pond by the width, if your fish pond is 6 feet by 6 feet then you have 36 square feet of surface area , each inch of fish requires 1 square foot of surface area so in our example we can add 36 inches of fish. When you purchase the fish they are often young specimens and they will grow so work out your stocking on the adult size of the fish, generally I tend to slightly under stock as this causes less strain on the filters and the general well being of the fish pond.

When adding the fish to your fish pond you should exercise patience and acclimatise them slowly, don't add all of your stock in one go, it is far better to add a few fish and then wait for a couple of weeks before adding any more. This will give the filters the time to enlarge their beneficial bacterial colonies to cope with the larger bio-load. The best time of year to stock your fish pond is in the spring as the water temperature starts to increase, stocking can continue through the summer months but once the water temperature starts to drop again it is best to refrain from adding any more fish.

The bags containing the fish should be floated in the fish pond for at least 30 minutes, this will allow the temperature of the water in the bag to level with the water temperature of the fish pond. Add some of the water from the fish pond into the bag after floating and keep doing this slowly before finally releasing the fish.

Taking your time at this stage will help the fish to settle quicker and prevent them from getting stressed.

There are many popular species of fish that you can add so here are a few examples listed below:

Common Goldfish

This has to be the most easily recognisable fish available and a very hardy species, having said that they still need care and decent water quality to thrive, once happy they should become prolific breeders in the fish pond. They belong to the Cyprinid family and are closely related to the Koi Carp and the Crucian Carp. There descendants were less colourful than the fish we know today but through selective breeding hundreds of years ago in China we now have this beautiful but underrated fish widely available. They are available in a large variety of colourations including a black and yellow morph but bear in mind that they are classed as high waste producers so the filtration needs to be able to cope with this.


These are classed as a single tail goldfish but every specimen that I have seen has a different myriad of markings and colourations making each one unique. Red, white, blue and black markings run along the body right through to the finnage and they are also classed as hardy but I do believe that they are slightly more delicate than the common goldfish. They originate from Japan, yet another species resulting from selective breeding and have been with us since the 1900's.

Comet Goldfish

These are often confused with the common goldfish but their finnage is more flowing and they can either have a redder colouration to their bodies or they are also available in a variety of colours including white, yellow and orange. They are extremely hardy and ideal for novice fish pond keepers as well as experienced keepers. The do not grow too large so are suitable for medium sized fish ponds and unlike the common goldfish they tend to leave the pond plants alone and do not disturb the roots. The only drawback with this fish is that when they do start breeding, they do not know when to stop and can quickly over populate your fish pond.

Golden Orfe

A beautiful fish but they are very greedy and very fast growers, adding these to a small fish pond will not work unless you have a larger fish pond to move them onto. They are very social with each other and other species of pond fish but if not given enough swimming space they have been known to leap out of the water. There is a variation to the Golden Orfe known as the Blue Orfe for obvious reasons and both species have excellent markings.


This fish is often overlooked but make a great addition to any fish pond as they tend to stay at the lower levels scouring through the muddy bottom looking for food and aquatic snails. Their colouration cannot always be admired from the water surface due to their swimming habits but they display a gold and green colour when viewed from the side is outstanding. They tend to be forgotten about in the fish pond but do a great job of cleaning up any uneaten food left over by the upper dwellers.
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Koi Carp

For the larger and deeper fish ponds there can only be one fish that comes to mind instantly and it has to be the Koi Carp, these fish are held in high esteem and some specimens can be worth thousands of pounds if they have the correct markings. They do grow large and have voracious appetites but are a pleasure to behold and give great satisfaction when viewed in the fish pond. These too are the product of selective breeding from the original drab carps and are now commonplace all over the world. To list all of the varieties would take a full article in itself but that will be included on this website in the near future.

Bear in mind that the construction of a Koi fish pond is more expensive than a basic design so unless you can afford the extra cost do not attempt to keep these fish, they do demand the best of everything including extra filtration.

The above are just a few examples of fish that can be kept in a fish pond but whichever species you desire to keep always select healthy specimens to add to the fish pond. Before you purchase them observe them in the tanks swimming around, they should have a smooth swimming pattern with their fins erect, their eyes should be clear and there should be no signs of fungal infections or sores. Ask to see the fish feeding, the food should be accepted straight away and with vigour, if they shy away from the food this is a warning sign of problems ahead.

Adding healthy specimens to your fish pond will prevent the spread of any diseases or infections and the fish will give you hours of enjoyment!

Question left on Sat, March 10, 2012 09:10 by GIOVANNA WATERWORTH

In the past three or four days the fish in the garden pond have risen to the surface but they are very slow, otherwise they look rather healthy, is anything wrong with them? Thanks for your help!

Answer by staff: The fish will be fine, it may take them a couple of weeks before their metabolism speeds up making them more active and everything depends on the water temperature. At the moment the temperatures are only just rising which the fish have sensed and this has allowed them to emerge from the safety of the lower depths of the fish pond.