The killer of koi: copper and zinc

The author believes that you are not surprised: copper and zinc in the water will kill koi. Of course, this is not news to the author. What the author means is that before you heard that copper-connected heaters released large amounts of copper into the water, thus killing all koi, did you think that copper and zinc would kill your koi? Maybe many of us haven't heard such a story yet. Before I tell you this, the author reviews some of his own history.

Of course, the author has been raising koi for quite a long time. The author uses a microscope to identify parasites and then deal with them properly. The reason for this is that the author lives in northern Virginia and does not have to warm the fish pond. However, every spring, the koi in the author's fish pond always explodes diseases. Every year. After the situation occurred, the author observed the disease with a microscope and found friends to cooperate with the sick koi.

When the author began to raise koi, the density of koi in the pond was a little high. However, after a period of upgrading, the density of koi in the pond has been very low.

In the summer season, the author changes water for the fish pond every other day. A heavy agent is applied to the large fish pond every day. Change the water for the fish pond even in winter. The filtration system of the author's two fish ponds is twice the standard of the manufacturer.

Despite the above measures, the same thing always happens every spring. Koi afflicted by disease. The outbreak of diseases this spring is even more than in previous years. During a change of water in February this year, a carp of five colors rose to the surface and died. The five colors were treated for an unknown ulcer on the operculum in September last year. At that time, the author and several of my friends did not find anything abnormal when they examined it with a microscope. In short, the five colors seem to have been cured. And put it back in the pool. But for some time in December last year, the temperature was too high, causing the green algae in the water to multiply too fast. Until March this year, the author could not clearly observe the koi in the pond. To make a long story short, the five-color koi was the first fish to ascend to heaven in 2007. In March, the author saw a relapse of the old problem of koi in the pond. What is annoying is that toads lay eggs in two fish ponds and found anchor worms on several koi. Therefore, medicine was given to kill insects in two fish ponds. In spite of this, the condition of koi is getting worse and worse. The author observed the scraping blade again with a microscope and still found no abnormality. At the end of March, the temperature dropped for several days and then rose again. The toad laid eggs in the pool again. There is reason to believe that it was caused by an anchored worm because an anchored disease had been discovered before. With a microscope, it seems that there are anchor worms, so once again kill the whole pool.

The condition of koi continues to be serious. The author began to treat the ulcer disease of koi. Some koi are treated with potassium permanganate. The author and his friends thought there were bacteria in the fish pond, so they injected some fish with Baytril. At this time, several koi are dead. The author has lost his head and doesn't know which fish are dead.

At this point, my friend suggested checking SVC and KHV. But the symptoms don't match. Exhausted, the author has begun to consider sealing the pool. After several months of twists and turns, the author asked himself whether he had the ability and intelligence to continue to raise koi. These questions have been asked to myself countless times: is the concentration of ammonia normal? Is the filtration system clean?

In retrospect, the author thinks about the SVC virus again. If the fish and water samples are sent to the epidemic prevention department and test positive, then the EPA will immediately come to the door and destroy all the koi and fill all the ponds.

In short, after discussing with my friends, the author decided to let the epidemic prevention department test fish and water samples because the author's best koi was dead at this time. By the way, all of this happens when the PH value of the water in the fish pond is fixed at 9.1. The author sent samples of fish, water in the pond, and tap water for testing. The results were mixed: no bizarre bacteria or viruses were found. However, copper and zinc were found in the water sample. As a reminder, the levels of copper and zinc do not exceed the standards that make people sick. However, the same amount of copper and zinc is enough to destroy the immune system of koi. In this environment, any bacteria will make the author's love carp sick and then die. Although the author exhausted all kinds of antibiotics, he could not bring his love carp back to life. In the absence of an immune system, sick carp are untreatable.

The author now uses Novaqua (water treatment agent, which is used to solidify heavy metals in the water, including copper and zinc to make it untoxic) to treat the influent of fish ponds. The next thing the author needs to do is to find out the source of copper and zinc in the water, whether it is permeated in the soil or from tap water.