On the road with two consultants
In this story, I will take you on a tour with the Koi and Pond Advisory Group. We visit a pond in which the koi behave differently after the owner’s holiday. Based on this visit, I want to give you some tips so you can go on holiday with peace of mind yourself.
This story is meant for all of us to learn from past problems so that they can be avoided in others.
We received a call telling us that upon returning from holiday, the fish were listless in the pond and one koi showed some strange spots on its head. From the amount of food left in the feed pot, it was clear that a lot had been fed. Whether someone could come and see what was going on now and the best thing to do.
Out and about with the Koi and Pond Advisory Service
An appointment was quickly made and on that particular day, we rang the doorbell at 16:00. After a brief introduction, the way through the living room to the pond follows. Here we find a narrow, sleek, yet cosy pond running the length of the garden. In the pond swim some goldfish, a tench and 3 koi. “Karel”, a hefty Soragoi, indeed shows spots on the head and dorsal fin that we would like to take a closer look at. The other two koi are an Asagi and a Showa. Both smaller, but still at least 30 cm. No injuries are visible in these fish at first glance.
Structured search for the solution
During each visit, we generally use the same steps to arrive at correct advice. In the process, we discuss the problem again in detail, especially observing the pond and the fish in it. In this way, we get a clear picture of the problem, for which we have come. Our first idea is that the excess feed has caused poor water quality and that is what started the problems.
TIP 1: Feeding during the holidays
If you are going on holiday for a period of several weeks, there is no harm in not feeding the fish at all. If you still want to continue (or have) feeding, you can consider a feed dispenser(*) or prepare weighed portions for the pond-keeper. It is also smart to feed together a few times and walk around the pond rather than just verbally transferring.
(*) Do not switch on a feeder just before the holidays but make sure it has been on for a few weeks and you are sure it is working properly.
Then the examination begins, going through all the questions on an Anamnesis form (checklist). Later, this is processed into a report, in which the pond owner can read back what we have seen and discussed.
Water quality
First, the quality of the water is tested. Ammonia, nitrite, nitrate, pH and KH. If warranted, we can also measure oxygen levels and check for iron in the water. The latter is only necessary if spring water is used when changing the pond.
At today’s pond, an elevated nitrite level is measured and the water is quite cloudy due to organic debris that has accumulated in the pond.
To keep the water quality high, it is necessary to change ± 10% of the water in a (koi) pond every week. This ensures that there is sufficient KH in the pond, which will keep the pH stable.
This pond “sat at the house” where the owner moved in early this year. And despite having already read a book on keeping koi, the need for refreshing had not become clear and therefore had not yet been implemented.
TIP 2: Refresh
In summer, give your (tub) plants pond water and then refill the pond with tap water. This way, you give your plants nutrient-rich water and refresh some of the pond water at the same time.
Pond water is changed weekly to remove accumulated (invisible) dirt and replenish the KH present in the pond.
TIP 3: Refresh during the holidays
If you will be away for less than three weeks, a ± 20% change before and after departure may suffice. If you are going away for longer, you could discuss with the pond-keeper how the refreshment process works.
Filtration
Then the filtration system is looked at. In this case, we are not dealing with a hi-tech koi pond. Under the decking is an ‘Oase Filterclear 6000’ pressure drum. It is set up below the water level and thus ensures that there is no pressure loss with pumping water around due to height difference.
Interested, we examine the pressure filter in terms of operation and flushing options. Based on googled information, we can fairly quickly explain how this filter works and how it should be cleaned weekly. Unfortunately, this appeared not to have been done for a while, a job that would be picked up right away the next day.
Remark:
In general, pressure filters are not a first choice when it comes to a koi pond. What often occurs in these filters are dirt accumulations, which in turn cause increased bacteria pressure. Frequent and frequent cleaning is therefore the advice with this type of filtering!
TIP 4: Filter maintenance during holidays
Make sure the pond-keeper knows how the filter works and what maintenance is required.
Fish
Then it’s time to take a closer look at the fish. The net and catch basin arranged for this visit are quite substantial in size. But rather too big a net than too small. “Karel the Soragoi” was caught quite quickly. The spots on his head are not too bad and the dorsal fin is also fortunately only irritated and not inflamed or damaged. When we turn the fish over and look at the gills, they appear to be somewhat lighter red. It is quite a shock for the owner when we find that “Karel” turns out to be a female.
A smear is taken and then the fish is allowed back into the pond.
TIP 5: Material
Make sure the right materials are available. A koi net, koi sock and a tank (in which the largest koi can easily fit) are part of the standard equipment of a koi pond.
Under the microscope, we examine the scraped-off mucus, we detect the parasite Trichodina and this discovery explains the abnormal behaviour. The parasite causes a lot of itching, which causes the fish to rub its body along stones and the bottom and thus gets the irritated spots on its skin. A second fish is also caught afterwards and undergoes the same check.
Conclusion
The picture is complete, now that we have examined everything we can draw a conclusion.
The combination of no water changes and the pollution present in the pond have taken a toll on the koi’s condition. It is possible that the excess feed over the holidays was just the proverbial straw, causing the koi’s resistance to be too low and allowing the parasite to strike. The filter needs to be cleaned more regularly and the UV lamp is broken.
By mutual agreement, it is decided to start by improving the living environment first. Weekly changes of 10%, with the first few times 20-30% to flush a lot of dirt out of the pond. Cleaning the filter and (replacing and) activating the UV lamp are addressed first. If this does not give any improvement in the fish’s behaviour within two weeks, then treatment will be considered.
TIP 6: General
Taking care of a koi pond requires some specific knowledge. If your (neighbour’s) pond nanny has no experience, it may be helpful if he/she can fall back on someone who does have this knowledge. If you don’t have friends or family who do have this knowledge you could look on facebook. Several koi groups are active there. You may be able to find someone here who lives in the area and could/will help your babysitter if needed.
This article also appeared in KoiWijzer and was provided by the Koi and Pond Advisory Group.
Text & photos: René Grootscholten
