Common Pond Emergencies and Their Solutions Part 3 – Diseases & Predators

sea photo

The ecosystem of a pond is very fragile and a human-designed pond requires your full attention to every detail. It can be the most natural looking and well-designed pond, but contamination, predators, and diseases are always a threat.

Common Pond Emergencies and Their Solutions

Whether you want it or not, as a pond owner, at some point you will have to face difficulties and emergencies resulting from a variety of contamination, predators, and diseases. We advise you to keep your cool and not to panic. Simply do your best to save your pond from any further damage and nurse your beloved fish back to health. You can always contact your local pond emergency team, and seek further assistance if you are not sure how to deal with the problem. At Mr.Fish, we are ready and available 24/7 to respond to your emergencies, and we can help you deal with the problem at hand.

Precautions You Must Take in Order to Avoid Diseases and Contamination in the Pond

Quarantine and Disinfection √

There are several things you can do to prevent any problems from occurring. The health of your Koi and other pond fish can be maintained if you follow the standard instructions for quarantining new fish and disinfecting new plants. You can find these here:

5 Things You Need To Do Before Introducing a New Fish Into The Pond
How and Why Should I Disinfect My New Pond Plants

Water Filtration √

Another important thing you must have in order to decrease contamination chances is to invest in a biological filtration system for the pond. To understand the basics of pond filtration systems you can read here:

Understanding The Basics of Fish Pond Filtration Systems

Water Parameters √

Regular checks for the parameters of the water, as well as maintaining responsible actions to keep chemical content balanced is a must. To find out the ideal water parameters for a balanced Koi pond check here:

The 8 Main Water Condition Factors For the Koi Pond

How to Deal With Pond Emergencies Like Epidemics, Poachers, Aggression, and Death

Disease Epidemic

trematode, koi fish, koi parasites,carp flukes, pond parasites
Trematode parasite life cycles. By Jack · derived from Wikimedia Commons

Sadly, it’s impossible to avoid crisis’s and outbreaks forever. At some point, you will have to deal with parasites. However, treating your water, tending to your filtration system, and following all quarantine and disinfection instructions, will surely lower the chances of this happening as often.

Fish are host to a number of them, and preventive treatments are our only protection. Water is the natural home for countless types of bacteria and a perfect environment for the accumulation of parasitic organisms. As an owner, your role is to look for signs of parasitic activity. Note that the symptoms below are not the natural behavior for any fish. Here are the common signs your Koi and other pond fish could be in danger:

  • The fish seem to be “rubbing” on the pond bottom, decorations, or edges. This will cause damage to the protective slime Koi have and will lead to further infections.
  • Your fish are hanging under the waterfalls. Usually, your fish will not go there as the motion and splash of the water are dangerous for them.
  • Your fish are lying on the pond’s bottom. Unless you have a pond of bottom dwelling fish, this is not a good sign. Most fish and especially Koi swim in the top levels of the water where there is more oxygen.
  • This can be a little bit tricky to notice right away, but fish too experience weight loss. However, the loss of weight can be a sign of parasites yet again.
  • If you notice your Koi are flashing you have to check your water parameters, but also check for parasites as this is a common symptom for both.
  • High levels of ammonia and parasites can both cause your fish to swim really fast, twist, rub or even try and jump out of the pond. Almost like it has gone crazy.
  • Your fish is isolating itself from the school and does not want to swim with the others.
  • Your fish do not want to eat. Unless it is the time of the year that they do not usually eat, this can be a sign of internal parasites.
  • If you notice any ulcers, sores, or lesions and missing scales on the fish body, this is a definite sign of either parasitic or chemical problems.

Koi Parasites Treatment

A severe outbreak of parasites in your pond requires treatment as quickly as possible. The treatment is different for each parasite but it must be noted that you need to seek a specialist in Koi nursing and treatment. Another thing you should immediately pay attention to and to fix is water quality and pond conditions, as they can also be the reason for many of the signs described above, and also help the parasites to develop faster.


raccoons, pond predators, pond fish, pond poachers, pond protection

Protection against predators native to your region is primary. If you notice you have less fish you will have to immediately take measures before the local wildlife gets accustomed to the free buffet. There are several ways you can predator-proof your pond and the sooner you do it the better. Do not wait for them to start poaching your fish before you take measures. For more information about pond protection from predators you can read here:


Aggression between species that are compatible and living well together is not unheard off if you are breeding the fish. However, for the safety of both the fish and the eggs, breeding should always occur in a separate breeding tank.

If you have already missed the step with separating you will have to remove the aggressive fish from the pond. However, this will leave the eggs unguarded. One more reason to breed fish only in a breeding tank.


koi death, koi parasites, koi maintenance, koi care, pond pollution, koi pond, pond cleaningSadly but inevitably death will crawl into your aquatic kingdom for one reason or another. You must remove the dead animal from the water as soon as possible and search for any signs of death to rule out that death was not caused from “old age”. Parasites, water conditions, predators, chemicals, equipment failure, and weather changes can all lead to this unfortunate end. We advise you to take all the necessary steps in avoiding such pond emergencies and seek professional consultations.