How Deep Should A Koi Pond Be?

Koi ponds are usually much deeper than ordinary garden ponds, often well over a metre at the deepest point. The right depth depends on the size of the pond and the number of fish, and we work it out with you at the design stage.

Can I Keep Koi In My Existing Pond?

Sometimes. It depends on the size and depth of the pond and the filtration it has. We can look at your pond and tell you honestly whether it would suit koi, or what would need to change.

Do Koi Ponds Need A Filter?

Yes. Koi produce a lot of waste, so a koi pond needs mechanical and biological filtration, and usually a UV clarifier to keep the water clear.

How Many Koi Can I Keep?

It depends on the volume of water and the filtration. Koi grow large, so it is best to start with fewer fish than you think and give them room to grow, and we can advise on this for your pond.

Can You Add A Waterfall To A Koi Pond?

Yes. A waterfall or a stream adds oxygen and movement, and the clean water returning from the filter often runs into it. We design it as part of the pond.

Koi in the clear water of the pond, beneath a cascade of stone and driftwood

Koi Ponds · Cambridgeshire

Koi Pond Construction

Depth, volume and filtration sized for the fish you want to keep, built so the water stays clear and the fish stay healthy.

Arrange A Visit Call 07568 488223

Built Around The Fish

A Pond Made For Koi To Thrive.

Koi are beautiful, long lived fish, and they need a pond built for them. They grow large, they produce a lot of waste and they need clean, well oxygenated water all year round. A pond that suits goldfish can quickly become too small or too dirty for koi.

We design and build koi ponds across Cambridge, Huntingdon, St Neots, Newmarket and Saffron Walden, planned around the fish you want to keep and the time you want to spend on them. Every koi pond we build is made to be enjoyed and to be looked after easily.

Pond Volume

How Much Water Is In Your Pond?

Volume is the starting point for sizing pumps and filters. Enter the size of your pond for a rough figure.

Deep enough for most garden ponds and wildlife ponds.

Getting there for fish. Koi need more depth and volume than most garden ponds.

Koi depth. Koi ponds are usually much deeper than ordinary garden ponds, often well over a metre.

Your Pond Holds

About 14,400 Litres

3,170 UK Gallons

14.4 Cubic Metres

RectangularRound Or Oval

Length

Width

Average Depth

A rough guide only. We measure properly before we size any equipment.

The finished pond built against an old brick wall

Why Koi Need Depth And Volume

Deeper water stays cooler in summer and warmer in winter, which keeps conditions steadier for the fish. Volume matters too. The more water there is, the more slowly any change in temperature or water quality happens, and the more forgiving the pond is. That is why koi ponds are much deeper than most garden ponds, often well over a metre.

Depth also helps protect koi from herons, which hunt by wading in shallow water. We plan the shape of the pond with that in mind, and suggest other protection where it is needed.

Filtration That Keeps The Water Clear

Koi produce a lot of waste, so a koi pond needs proper filtration. A mechanical stage catches solid waste, a biological stage turns harmful waste into far less harmful compounds, and a UV clarifier stops the green water caused by tiny algae. We size each part to the pond and the fish rather than to a standard kit.

The pipework and equipment are laid out so they can be reached, cleaned and serviced. A filter that is hard to get to is a filter that does not get cleaned, and it is the fish that suffer.

Koi Ponds

What We Offer.

Depth And Volume: A pond deep and large enough for koi to grow, with steady water temperatures through summer and winter.
Filtration: Mechanical and biological filtration sized to the pond and the fish, usually with a UV clarifier for clear water.
Water Movement: Pumps and returns placed to keep the whole pond circulating, with no stagnant corners.
Viewing And Access: Edges and seating planned so you can watch and feed the fish, and reach the equipment easily.
Heron Protection: Depth where herons cannot wade, and netting or other protection where it is needed.
A Careful Start: Help getting the pond started, and advice on testing the water and introducing the fish.

A formal pond set into a patio, lit from below by underwater lights at dusk

A Pond You Can Enjoy

Koi ponds are as much about the people as the fish. We plan seating, viewing points and edges so you can watch the fish and feed them by hand, and we can add a waterfall or a stream to bring sound and movement to the pond. LED lighting lets you enjoy it in the evening too.

One of our recent ponds was built against an old brick wall, with a cascade stepped down into it. Boulders were set to carry the fall, the edges were finished with cobble and planting, and once the water had settled the koi went in. It has looked after itself without chemicals ever since.

Renovating An Existing Koi Pond

If you already keep koi and your pond is leaking, struggling to stay clear or simply too small, we can help. We renovate and rebuild existing ponds, upgrade filtration and pumps, and carry out full clean outs, with the fish kept safely in holding tanks while the work is done.

Read more about this work on our pond renovation page, or see how we approach new builds on our pond construction page.

Common Questions

Questions About Koi Ponds.

Any Other Questions

07568 488223 More Questions Answered

: Koi ponds are usually much deeper than ordinary garden ponds, often well over a metre at the deepest point. The right depth depends on the size of the pond and the number of fish, and we work it out with you at the design stage.
: Sometimes. It depends on the size and depth of the pond and the filtration it has. We can look at your pond and tell you honestly whether it would suit koi, or what would need to change.
: Yes. Koi produce a lot of waste, so a koi pond needs mechanical and biological filtration, and usually a UV clarifier to keep the water clear.
: It depends on the volume of water and the filtration. Koi grow large, so it is best to start with fewer fish than you think and give them room to grow, and we can advise on this for your pond.
: Yes. A waterfall or a stream adds oxygen and movement, and the clean water returning from the filter often runs into it. We design it as part of the pond.

Where Next

A pond drained back to its liner and being cleaned out by hand

Pond Renovation

Leaks found and fixed, liners replaced, silt cleared and tired ponds brought back into balance.

Get In Touch

Tell Us About Your Garden.

Send a few lines and a photograph if you have one. We will come and look, talk it through on site and send a written quotation afterwards.

Arrange A Visit 07568 488223 info@riverrockwatergardens.co.uk

Where We Work

Koi Ponds Across Cambridgeshire.

Based at Willingham, we work across Cambridgeshire and into Bedfordshire, Suffolk and Essex.

All Areas We Cover