02. What you need to farm koi

I have farmed koi on a hi-tech farm that was already up and running, and have designed and built an ornamental carp farm from scratch. In either situation, it is easy to underestimate the real costs involved in setting up (and in the first case improving and enhancing the production facilities).

At only step 2 in this series, we’ve already reached the stage where fantasy meets reality. This is your first test to determine how serious you are about farming koi for a living. You may have sketched out (or dreamt about) how many ponds you will need, where they might best be located, the number and varieties of broodstock as well as where you’ll source your farm’s water. But be warned, there are lots of gaps in the middle that need researching and filling for your plan to be complete. We are going to list the major issues and areas for investment and planning here, but please bear in mind that this will probably only account for 50-60% of your total investment – and a good 12 months before you’ll start to see any income in return.

A few assumptions:

Following on from the previous article, from now on we will assume that we are planning to farm koi on a semi-intensive basis; inducing our koi to spawn artificially and growing on the fry in mud ponds. This then helps to determine our shopping list, but also dispels the suggestion early on that koi can be farmed on the scale required in a back garden. So what do we need to farm koi?

1. Money.

How are you going to finance your enterprise? What are your funding options? In both cases where I have farmed koi, fortunately the farm investment was underwritten by a financial backer (sleeping partner), and having seen the fickle nature of koi farming, I would still not invest my own money in a koi farm. A good koi farming business plan should factor in a complete wipe-out one year in every seven (so say aquaculture statistics – and something we have started to see for ourselves with KHV). Having said that, when koi farming is good, it is very good (and equally bad when things are bad). If I was looking at farming koi again, I would definitely seek a financial backer. This reduces your risk, but also reduces your own personal profit when things do go well. A partner may not be required to contribute hard cash, but might be a land owner (or even a farmer) who has surplus or under-performing land. You will have noticed by the increase in farm play parks, organic farms, adventure farms, golf courses etc that farmers are looking to diversify like never before; perhaps this could be your opportunity.

But if you still want to go it alone, then once you’ve seen the figures involved, you will either have to have received an enormous redundancy package or won the lottery. But if money is still no object – let’s compile your shopping list.

2. Suitable land. Buying land isn’t a typical purchase – If you end up not liking what you’ve bought, you can’t exactly take it back for a refund! But before you contemplate buying any land, you will need to know what to look for.

a. Clay site. In order to hold water, your site must have a clay content of at least 40%. If you find a potential site that is not clay-based then it will not support a koi farm, so move on.

[TIP. How to establish whether your proposed site has sufficient clay content for a koi farm.

1. Remove the top soil until you get down to the harder subsoil. Do this in several areas across the site. From each sample hole take a sample of subsoil.

2. Place some of your sample into a clear bottle and fill it with water.

3. Shake vigorously until all of the soil has been fragmented and suspended in the water.

4. Place the bottle down and wait for the suspended soil to settle. The last layer to settle will be clay.

5. If the top layer is at least 40% of all of the layers in the sample, then your site will be suitable for a koi farm.]

b. Topography. If you have a look at where the ponds in Niigata are situated, you would be led to believe that your ideal site should be alpine in its topography. But remember that the Niigata koi farmers were rice farmers first who have progressed on to koi in that same original mountainous terrain. In contrast, you should be looking for a gently sloping site (rather than dead-flat) as the slight gradient will make it possible to drain your ponds by gravity (and that’s for free!)

c. Size. A useful rule of thumb when trying to size your farm is to know that a 50m x 10m pond can raise between 5000 and 10000 2-3” koi from fry. Ponds this size are ideal as nursery ponds, but larger ponds will be required for broodstock and growing on 2nd, 3rd and 4th year koi. On this basis, you should be looking for a site no smaller than 4 hectares to support a small enterprise allowing for say 10 (50m x 10m) nursery ponds, 10 (50m x 50m) growing on ponds, with further space allowed for broodstock ponds, a hatchery building and further ponds should they be required.

d. Location. One of the biggest factors that will affect your productivity is local temperature and climate. As you travel north in the UK, the number of carp farms tails off, showing that the best growing conditions are in the south. Having said that, my two koi farming experiences have been in the north west and east midlands where productivity and growth rates were more than satisfactory. Another key requisite for your location is that it must be near a suitable water supply.

3. Water. You will have two mandatory water requirements. It must be of the correct quality and available in the desirable quantity at specific times of the year.

a. Quality. Your water source should be a reliable, consistent quality. It must be disease-free (and also free of fish) and ideally hard/well buffered as this will help your water chemistry within the mud ponds.

b. Quantity. Bearing in mind that a single 50m x 10m nursery pond will hold over100,000 gallons (at 3’ deep), you will soon come to appreciate the volumes of water your source is going to have to supply. Furthermore, because of the tight timing and synchronisation required between spawning in the hatchery and stocking the fry in the nursery ponds outside, each of your nursery ponds by about May must be filled at the same time – and quickly. This ensures that you have a reliable handle on what stage your ponds are with respect to their maturity (and live food content). If your ponds are filled too slowly, then the first will be out of step of the ones filled later on – giving you unpredictable live-food results when stocking out your irreplaceable fry.

Water sources. What are your options?

a. Tap. Excellent quality, and a reliable source. But, it is not available in large quantities, and if metered will prove to be expensive. Having said that, one of the Environment Agency’s farms in the North West relies on tap water to supply its hatchery.

b. Spring. Good quality water, but may be unpredictable in supply. You could collect it in a reservoir over the preceding months, but this is an added complication and expense.

c. River. You will not be able to site your farm too close to a river due to the flooding risks (and the risk of you introducing non-native fish into a river). If a river is your choice of supply, you will have to pump and pipe it over significant distances. But I would advise against using a river as your water source because it will have an unreliable and very changeable quality and because it will contain fish it is likely to be a source of disease.

d. Well/borehole. These are my preferred option. They supply good quality water, reliably and will be disease-free. You will probably have to drill one (not getting much change out of £10,000) and test pump it to check that it delivers sufficient water. There is always a possibility that you will drill a borehole and it not supply the water you require!

All water abstraction (from spring, brook, well, river or borehole) is subject to the Environment Agency granting you an abstraction licence – and you paying for the volume of water you abstract. The licence will also detail when and how much water you can abstract. Remember that your peak water requirements will be between April and July.

4. Broodstock

Your investment in broodstock will be determined by your koi farming strategy. Whether you are seeking to farm top quality koi or ghost koi. Understandably, the broodstock for a high-end koi farm will cost significantly more than the stock for producing ghost koi (metallic koi x carp crosses). Be aware also that top quality koi will not necessarily produce top quality offspring – remembering that koi genetics is one of your largest hurdles to overcome.

How many? This will be determined by how many nursery ponds you have, and again, by what quality of koi you are seeking to produce. If you are seeking to farm recognised varieties, then you will need to buy matching male and females of that variety – ideally from the same bloodline. You can never have too many broodstock, but from experience, there is nothing more frustrating than not being able to fill a field full of nursery ponds for the lack of eggs or fry. Another rule of thumb is that a 1.5Kg female will produce approximately 100,000 eggs, the fry from which would then populate a single nursery pond, looking to raise a final 5-10000 one-year koi from that spawn.

Now onto the things you’ll need that money can’t buy.

5. Practical experience.

I spent 5 very enjoyable years at Brooksby College helping to establish a new Fish Farming and Aquatics Dept, part of which involved designing and constructing a ghost koi farm. The farm was built so we could self-finance the department but also so the students could gain valuable hands-on koi farming experience.

Experience is the only way of gaining the skills that you will need to apply later to your own farm if you want to make a living. For example, look at the picture below (Fig 1) and see if you can answer the ‘what, why, when, how and where’ of what is happening in the picture? I suggest that you will only be able to answer and perform each of the aspects covered through experience.

What. What sex is the koi and what is going to happen to it next? This is a female, and she’s about to be injected with hormone.

Why. Why is she upside down and easy to handle? She’s been anaesthetised.

When. When do you anaesthetise a koi and when do you inject her? (See Step 3 + 4 later on in the series)

How. How do you inject or anaesthetise a koi. How many times and for how long? (See Step 3 + 4 later on in the series)

Where. Where do you inject a koi? Where are the eggs and sperm going to go? (See Step 3 + 4 later on in the series)

6. A little luck and a ‘following wind’.

At times in your life as a koi farmer you will need to be fortunate with certain sets of circumstances. For example:

a. Females. You will soon notice as this series progresses that the koi farming calendar revolves entirely around the your female broodstock. They are kept in excellent mud-pond conditions and manipulated to spawning by tinkering with their environment, finally injecting them with hormone. But if a female doesn’t respond (known in the trade as having a ‘headache’) or she delivers few or no eggs then there is nothing more you can do to make her more productive this year. All you can do is return her to her pond and try her again in 12 months time.

b. Nature. There comes a time when 2-3 week old fry that have been raised in your enclosed, warm hatchery need to be stocked into your highly productive, live-food rich nursery ponds. While the fry have been in the hatchery, your mud nursery ponds will have been ‘stewing’ to produce a live food banquet for the fry. But if the weather during this period has been changeable and unpredictable, then it will have been difficult to judge when the ponds will have been ready to accept the fry. Likewise, once the fry have been stocked out, they are at the mercy of the weather, with their first few days outside being a real heart-in-the-mouth period.

However, if all goes to plan, what were nothing more than ‘slivers of glass’ when you lost sight of them as you stocked them into the thick green pond 10 days ago, can now be seen from 10 yards away (so great has been their growth rate). You should hope so. Remember, those fry are your farm’s income for next year!

Next month: You’ve planned, bought and constructed your koi farm – so how do you actually go about farming koi?

Kill blanketweed and string algae.