How to Create Your Own Trout Pond in Your Garden

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Keeping Trout in Ponds is Different: Over the years I've often been asked about keeping fish other than koi and goldfish in garden ponds and especially trout. Of course it is possible to keep trout in an artificial environment.

Requirements for keeping fish like roach, perch, kurper (South African bream type of fish), bass, sunfish, rudd are not too different than for keeping any type of carp (this includes koi and goldfish). However trout are different and I will explain what's required to have a successful trout pond on a step by step basis.

If you would like help in specifying the actual equipment then contact me by email. This is a good email address to use pondprof(at) for this purpose. If you fly fish for trout click here.

 The Difference Between Trout and Other Fish The major difference and it is a vital one is that Trout need about 15-20% more oxygen in the water than most other pond fish. They have a different metabolic system that requires high levels of oxygen.


They generally need a different diet higher in oils. The picture shown here is of a trout pond in British Columbia ... click to enlarge. It belongs to Ed Wright and I'm sure you would love to see more of his beautiful home ...

*****While we are not talking of breeding trout it still remains that these fish can only successfully breed in cool, well-oxygenated running water. These conditions do not exist in ponds.

Trout still show signs of breeding behavior in ponds and they still manufacture eggs and milt. They also mimic the way they compete for a female's attention at spawning time (autumn to winter to spring).

So these are important differences and we can translate these into pond requirements to be able to be successful. Once I've explained these then I'll put this into context by suggesting the type of equipment to consider buying.

Pond Conditions

The water temperature should ideally never exceed about 18 degrees C (68 degrees F). This is to ensure that the water can hold enough oxygen. The colder the water the greater the amount of oxygen it can hold.

This is why trout are found in the most beautifully scenic parts of the world ... and why catching trout on fly is so popular.

Temperatures favoured by koi carp and goldfish tend to be in the mid-twenties.

Trout may survive in water at somewhat higher temperatures but they will not be happy and may well suffer and die.

This means the ideal trout ponds will be in cooler climates such as northern Europe, USA and Canada. These areas may exhibit winter freezing conditions. This means the pond has to be emptied for the winter and the equipment properly stored. In this case the trout have to be released or handled some other way.

Where I live it would be almost impossible, in a garden pond, to keep trout that would survive a complete summer.

You will need to feed trout a bit more food than other types of fish since they are more active and consume more energy. This means the filtration and UV system must be larger than for a normal fish pond.

You should install a much more powerful pump and a good waterfall or stream inlet to a trout pond so that stream action is mimicked.

Trout enjoy running water and the action of a waterfall improves the rate of absorption of oxygen into the water. Trout need to exercise and swimming against an artificial stream creates an ideal "treadmill".

You should add extra oxygen to the water by means of an aeration system (air pump) and continuously blow air into the stream or waterfall and if possible, the filter as well.

By the way you will never have a mosquito problem in your pond if you keep trout. In nature the mosquito larvae provide a very high proportion of the fish' diet.

The Equipment for a Trout Pond

This is no different than for any other pond with significant exception that you need to use higher capacity pumps, filter and UV.

Let's use an example. Say you have a pond 12 feet x 10 feet x 4 feet deep. This is about 3.7 metres x 3.1 metres x 1.2 metre deep. Here's what I would recommend you do to size your equipment. First here's the approximate volume of your pond:

Cu ft: 480 Imperial Gallons: 3,000 US Gallons: 3,750 Litres : 13,600

Now to specify the filter and UV equipment think of your pond as being twice as large. In other words get a pond filter with capacity to handle a pond of 6,000 Imperial or 7,500 US Gallons or a pond of 27,000 litres.

This may sound like overkill but trout are beautiful yet fickle creatures in an artificial pond and you need to be able to purify water and maintain stable conditions as quickly and consistently as possible. You need equilibrium to be maintained. You will not do this with a small filter system

For the Ultra Violet Light unit, called an UVC, getting a unit sufficiently big to handle your actual pond volume is OK. However going a bit bigger will help not hinder. An UVC ensures your pond stays crystal clear by killing suspended algae.

Now for the pump: I would suggest you get a pump that will pump at the very least the actual volume of your pond per hour. In other words if your pond is 3,750 US gallons then the smallest pump you should consider is one that pumps 3,750 US Gallons per hour at the head your are operating at. By this I mean if you are pumping to a waterfall 4 feet high then the pump must deliver the volume at 4 feet (preferably 5 feet) pumping head. I hope that's clear because it's important.

Make sure you run the pump 24/7. Pump all the water through the UV and filter. If this is not possible then split the flow to send as much water as possible through the filter.

If your water temperature does not exceed 16 degrees C then you can probably get away without an air pump for the trout pond. Nevertheless I would still recommend one. Pump air into the pond and waterfall header and filter if possible using a manifold arrangement.

An Actual Example

A 2 pond system. Pond 1 is 6000 US gallons, Pond 2 is 1200 US gallons. Waterfall 10 feet high (above water surface)

See list of links at the end to explore if you're looking for good equipment to buy.

By the way get my free calculators if you want to convert units. Here are the links

1. Volumes and flow rates: 

2. How to work out the volume of your pond:

Total pond volume in example is 7,200 US gallons.

So recommended pond bio-filter capacity is not less than 14,000 US gallons. If you are money conscious use smaller filter and stock less fish in your pond. Seems a pity to do this. Biofilters can be reasonably expensive but since the filter acts the same way as your kidneys do, removes all the waste and toxins secreted by the trout, then consider getting the best you can afford. Since filters need regular cleaning you can save yourself hassles by getting a pressure filter that is easy to clean by back washing ... much like a pool filter.

UVC light system (very often this comes complete with filter system and this is better way to buy actually). It must be able to handle 7200 US gallon capacity minimum. You must change the lamp every 8000 hours (ie every year in full use).

Pump: very minimum of 7,200 US gallons per hour and I would tend to want to increase this to about 10,000 by using 2 pumps each of 5,000 US gallons capacity. It's always best to have 2 pumps as you will learn in the articles you're getting.

Use submersible pumps to save a lot on running costs. Oase and Hozelock brands are excellent, reliable and efficient with good guarantees.

In this case the chosen pump(s) must deliver this volume at 10 metres head. If you're going to use 2 pumps then pipe one straight into the pond to create a streaming effect in which case your first pump would be minimum 3,600 US gallons per hour at 10 feet head and the second one would be 3,600 US gallons per hour at 1 foot head. This second pump would be smaller and cheaper both to buy and run. It also acts as a spare in the event one breaks down.

That's about it. If you pipe these into the system you'll have a great trout pond. It will always be clean, clear and healthy.

Links to detailed info on equipment selection.

Large biofilters and UVC ... top class, low maintenance, large pond filters

Smaller Biofilters and UVC ... how to select smaller filters and UV combos

Pumps ... pump selection

You'll see links on my web pages to UK and USA suppliers I trust and recommend.