08. Koi keeping success. Avoiding common problems.

The vast majority of problems in a koi pond a can be traced back to water quality. As this vital topic has been discussed in previous articles in this series as well as its impact on koi health (and how to respond to disease), it gives us an opportunity to look at other types of problems in a koi pond.

In Step 8, we will take a wider look at some of the more common problems we may encounter in and around our ponds, and how we can avoid them. Some problems are more common to us all that even with our best efforts, we are still likely to experience them. As we will see, in these instances, there are recognised ways of confronting and solving these problems.

Problems that we will encounter as a koi keeper can be divided into three groups. Problems with your pond and filter system, problems with your water and finally problems with your koi.

1. Problems with your pond and filter system.

a. Know your pond’s vital statistics. Almost every koi pond and filter system will be unique in design and volume as they are built to different depths, contours and budgets. To avoid problems in the future and to be able to address problems when they occur we must know the volume of our pond. This will allow us to make accurate dosing decisions when a pond treatment is required and will prevent either under or over dosing, ensuring that all treatments are used as effectively as possible. Furthermore, your pond’s volume is required to calculate the required turnover rate of our system’s pump, and the wattage required for UV or electric heating systems.

If life was easy, all ponds would be regularly shaped, allowing easy calculation of your pond’s volume once it has been built and filled. However, as most ponds have sweeping sides and may vary in depth, it is not possible (nor responsible) to guestimate your pond’s volume. The most accurate and reliable method is to fill your pond up the first time through a water meter. This will give you an extremely accurate pond volume.

Remember to fill your pond to the brim initially because if you were to under fill a 20 ft by 10 ft pond by two inches your estimation would inaccurate by over 200 gallons.

b. Auto top-up: Simple and effective. One of the most common headaches is the drop in a pond’s water level experienced over time through evaporation. This of course is most pronounced in summer (or in a heated pond in winter), and especially with ponds that incorporate a waterfall. Even though this does not affect the health and life of a pond it creates an aesthetic problem, where over time unappealing areas of black liner or fibreglass become exposed below a tidemark. This is a far greater problem where rockwork has been used to mask the pond edges to disguise the artificial nature of the pond. In these circumstances, if the water level is allowed to drop, it is similar to catching a glimpse of strings during a magician’s illusion.

If your filtration system sits alongside your pond, and his gravity fed, then an auto top-up mechanism can simply be installed using at DIY plumbing kit similar to that used in a WC cistern. Once installed, you can rest assured that your pond will be brimming for ever more come rain or shine.

c. Pump Standby. A koi keeper is not dissimilar from a boy scout in that they should ‘be prepared’ for problems that could easily arise in the future. Pond pumps that are currently available on the market are arguably the most reliable they have ever been, but they still have a limited life. Even if your pump is supplied with a five-year guarantee, should it break down within that period you may still be without a pump for days – even with the fastest back-up service from a manufacturer. In aquaculture, where the value of stock in many recirculation tanks may not be as great as that in a koi pond, the practice of carrying a spare pump is routine, realising that for the stock to remain healthy, if the pump fails, a quick change is essential. In a similar way, every responsible (and financially prudent) koi keeper should make the same calculation of comparing the cost of a standby pump with the value of their koi (or at least the cost of treating them through a period of poor water quality that is likely to follow a pump failure).

2. Problems with water quality.

a. Better quality water at source. The most frustrating aspect of maintaining a pond environment can be not having complete control over all factors that can affect water quality. In this way, even if you know what is required in your pond, circumstances may dictate that you are not completely able to provide it, having to accept a compromise. A compromise between the ‘ideal’ and the ‘acceptable’ happens as soon as you turn on the tap to fill your pond. We know that the tap water is safe to drink and with a dechlorinator is acceptable to our koi – but is it ideal? I am convinced that many subtle chronic problems (such as reduced growth rate, lack of vibrancy in colour, lack of vigour etc) not only go unnoticed by many koi keepers (because they are not as tangible as an outbreak of disease) but also are caused by poorly sourced water. Untreated tap water can introduce low levels of contaminants by stealth which will accumulate over time. Although this may not be an obvious problem in your pond, it can be eradicated by installing a water purifier in line between tap and pond so that all water entering your pond is closer to ‘ideal’ than ‘acceptable’, reducing koi health problems in the future.

b. Saltmeter / Refractometer. Perhaps not at the top of every koi keeper’s list, but how else can you verify the concentration of salt you may have dissolved in your pond? A refractometer will not necessarily solve pond problems, but it will help you prevent them by providing you with an accurate reading of the salt dissolves in your water. For those koi keepers who prefer not to use salt in their pond this does not present a problem, however if you do, salt levels can prove impossible to track when taking into account factors such as evaporation and partial water changes.

Those koi keepers who do prefer to maintain a residual salt content, levels must be kept within recognised bands, and without a refractometer, it becomes sheer guesswork. They are simple to operate, very accurate and use daylight – so no batteries needed!

c. Surface foams and frothing water. In the same way that a falling water level can spoil the aesthetic impact of a pond, so too can a surface foam. However, unlike a variable water level, frothing water can also be an indicator of a water quality problem that may eventually have a chronic effect on the health of your koi. Frothing is caused by an accumulation of dissolved organic compounds (loosely and collectively called ‘proteins’) that are attracted to the water/air interface of bubbles, stabilising their structure and preventing them from bursting. The dissolved organic compounds can be removed or reduced by a partial water change or by installing a pond protein skimmer. Alternatively, you could reduce the symptoms of foaming (rather than the cause) by using a surface skimmer that would remove the stable bubbles and foam from your pond’s surface.

3. Problems with your koi.

a. Avoiding unnecessary treatments – get to know your koi better.

Even if you know your pond’s volume accurately, and have dosed it with the correct concentration of treatment, you might well still be using medication and necessarily – potentially stressing your koi. So how would you know that the symptoms our koi are showing are caused by a pathogen?

Confusion could easily arise with koi that are or scratching – is it irritation caused by parasites or by nitrite? The only way you can confirm this is by possessing and using a microscope. These are now more affordable than ever before and are irreplaceable when needing to positively diagnose an external disease problem. If you are someone who tends to medicate their pond ‘just in case’, then a microscope will soon start to pay for itself in saved medications.

A microscope can be used for routine scrapes on your koi (just as you might comb a cat periodically and check the comb for fleas). You’ll be surprised at how adept you will become at identifying different parasites, and also judging whether the density of parasites on a koi merits treatment. You will also discover another aspect of your koi’s individuality when using a microscope. Besides possessing different patterns, characters, and appetites, your microscope will also reveal how some of your koi are more prone to disease than others. You will be amazed at how two koi in your pond will show different levels of disease.

2. Keep a log or koi diary. In the same way that keeping a spare pump is learning from aquaculture, so too is keeping a log. This will enable you to spot patterns in behaviour, or retrace your steps when trying to workout what you have done differently in the event of a problem. In the same log you could make a note of your pond’s volume, dates of treatment, treatments that have proved to be most successful, changes in diet, date a pump was installed, date you changed a UV bulb, date you started or stopped feeding in spring and autumn etc. This will soon become an invaluable management tool, enabling you to perfect your koi keeping, foreseeing problems and ideally prevent them from happening.

We are all likely to experience a range of different problems when keeping koi – some more substantial, others simply irritating and yet in most cases there are ways we can improve our chances of foreseeing and even preventing them from occurring. But if the inevitable does happen, equally there are ways that we can effectively confront and solve these problems, being aware of what caused them in the first place.

Kill blanketweed and string algae.