Jul 2003 21 Years of Koi Keeping Selected Articles

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From the President to the N. F.K C. Members:   We had a lively gathering at the hall. There were a lot of different kinds of things for most who attended. I hope everyone found something that they could use. Thank you to all that attended.

Lets all remember this meeting is on SATURDAY at 6pm. Chairs are provided at this meeting. This is the club sponsored dinner / summer party with an USA theme. The club will provide the meat, dinnerware, and the drinks. Anything else is up to you. Remember PLEASE NO ALCOHOL. Till we meet again, Tim

 Secretary's   Report By Todo: : 24 Members at last meeting.

With the July meeting having no business there is little to report in the minutes. Tim announced that Rod Lawton had lost his son and needed help.

 What is a Koi Pond     Koi ponds may be full of water like their garden pond cousins, but there are extra points to consider to ensure a healthy home.

Like a garden pond, a koi pond is also a hole in the ground filled with water, but the resemblance ends there. A koi pond has a single purpose: to provide a suitable environment for keeping koi. And because koi are fast growing fish who produce a great deal of waste, the main aim is to create and maintain a large volume of clean well-oxygenated water in which they can flourish and show off their colors. A koi pond should be a least 4 feet deep and to keep the water clean, it must have a filter system that can cope with the heavy demands the koi will put on it. Unfortunately, since koi will disrupt any plants in the pond, the clean functionality of a koi pond cannot be softened by the addition of aquatic plants, unless they are grown in protected zones.

Of course this does not mean that a koi pond should not please the eye and become an attractive garden feature, but it will generally take up more space than a garden pond and require more services and equipment such as the filter system, water supply, drainage pipe-work, electricity supply for pumps, heaters and water treatment devices and generally be more complicated and functional.

A successful koi pond is basically a water treatment plant with fish swimming in it. If you can make it look good at the same time, then you have succeeded on all fronts.

Once you have decided to build a koi pond, the next most important decision is where to put it. Beside purely aesthetic consideration, there are a number of other factors that will influence your choice of location. Here we consider them in turn.

What lies beneath.    Building a koi pond involves a major excavation of the soil in your garden. Clearly, you need to check what lies beneath the surface before you start digging. The main obstacles will be water supply, gas pipe-work, electricity cables, rainwater soak aways, manhole and tree roots. You may need to look at your original building plans or consult the local utility companies for advice on the location of services to your property.

Connections to utilities.    Having discovered where the , gas, and electricity supplies ruin you garden so that you can avoid disrupting them when you excavate the pond, you also need to make sure the pond is conveniently located for connection to them. A koi pond will need a water supply for filling and topping up, a drainage system for carrying away waste water, an electricity supply, pumps and other essential equipment, and possible a gas supply if you plan to include a gas –fired water heating system. If your first choice of location makes it difficult to install these essential services, then think again. It may be better to choose a compromise location to avoid having to dig up that recently laid patio. And always think ahead: you may wish to upgrade your system in the future and you should establish that electricity cables, for example will be able to carry a higher load if you install more pumps or additional water treatment devices.

Gain access to the site.    Even a relatively small koi pond entails the shifting of a great deal of soil. Unless you enjoy the backbreaking process of digging the cavity out by hand , you will want to use a mechanical excavator. You can hire small diggers that will fit through boundary openings as narrow as 39 inches. Check that your site allows access for such a machine and you have space to remove any excavated soil that you are not keeping to make a rockery or waterfall feature in the garden. You may need to remove some fence panels during the building process to improve access. If you are not confident about using a mechanical digger you can hire one complete with an operator to carry out the main excavation work. Although relatively expensive, this will be money will spent to get the project underway.

Position in the Garden      Of course, the main point in building a koi pond is so that you can en joy it. Therefore, choose a location that allows you to view the fish easily on a day to day basis. And you will need to provide easy access for routine maintenance so even during the cold, wet days of winter. So avoid building the pond in that remote corner of the garden that you rarely use: otherwise you will remember why you never use it! Also consider the position of established trees in the garden. These and other plants may shed leaves into the water that will block up surface skimmers during the autumn and winter. Left in the water, they will rot down and cause pollution problems for the fish, Where suitable place the pond reasonable close to the house so that you can watch the fish from your window on colder days. But if you do this, take care not to undermine the foundations of the house or any nearby building during the process.

What type of pond construction?    Depending on your preference and your budget, you can build a koi pond in two main ways: lining the cavity with a flexible sheet of specially formulated plastic or rubber material, or building up the walls of the pond from concrete blocks on a concrete foundation slab and then lining this with a flexible liner, painting it with a pond sealant, or bonding sheet of fiberglass matting onto the walls with an adhesive resin.Water Gardener, April 2003

AMMONIA MACHINES:   KOI CAN OVER EAT  David Dec (davedec@decinc.com)

Koi make ammonia from the food they eat. Koi are sometimes referred to as ammonia machines. The reason for this is because of the quantity of food they eat. This ammonia is made in several different ways:

Koi respiration introduces ammonia through the gills, urine and feces.

Un-eaten food decomposes into several chemicals including ammonia.

Sediment on the pond bottom, consisting of feces. Plant material from within the pond as well as windblown leaves and other dead organisms, also generates ammonia.

We feed just the proper amount of food each and every day, which establishes a “Steady State” condition producing the same amount of ammonia each and every day. Once we know the weight of wood we feed each day the calculation becomes easy.

Koi eat a 1% to 2% of their body weight in food each and every day, but the calculation should be based on the actual weight of food we feed daily.

The protein content of Koi premium pond food is typically 36%, but sometimes is as high as 40%.

The nitrogen content of protein is typically 16% (the Kjeldahl Analytical Method is based on this).

So multiplying the weight of the food by the % protein, and then by the % of nitrogen in the protein, we know the weight of atomic nitrogen going into the water.

If we know the volume and thus the weight of the water, we can then calculate the ppm of nitrogen.

A few calculation based on these assumptions for a typical Koi pond, show that this results in the production of 1.6 ppm of atomic nitrogen every day.

a. This creates 1.9 ppm of ammonia

i.(4.3 ppm fir 2% food – 40% protein)

b. 1.9 ppm of ammonia creates up to 5.2 ppm of nitrite

i.(11.6 ppm for 2% food-40% protein)

So each day we generate 1.9 ppm of ammonia, and up to 5.2 ppm of nitrite. When we measure the amount of ammonia and nitrite actually present, we know the difference is the amount “digested” by the bacteria daily.

If there are no bacteria to digest the ammonia and nitrite, and there are no water changes, then the ammonia concentration will increase by 1.9 ppm per day, the nitrite by up to 5.2 ppm per day.

Under these conditions the Koi will soon die from the toxicity of ammonia and nitrite. A couple of weeks in water over 20 ppm of ammonia and nitrites and we will have mostly dead Koi, the ones still alive will have Columnaris and Aeromonas infections, such as hole in the side disease, fin rot, tail rot, secondary fungal infections, etc.