Springtime Health Risks for Koi
Springtime is the most critical time to be testing your water on a regular basis.....meaning weekly at minimum! Depending on where you live in the country this is also the time to restart your filters and pumps if you have shut them down for winter. When the water is below 40 DF this is not as critical, but as soon as the water starts creeping above 40DF and holding you want to restart the sytem and keep it running 24/7 for the rest of the season.. This is because ammonia that is nontoxic below 40 DF will now become more and more toxic as the temperature rises above 40DF. The warmer it gets the more toxic the ammonia becomes. Remember it takes from 4-8 weeks on average for your filter to cycle completely and biologically remove toxins like ammonia and nitrite from your system. It is for this reason that you need to have your system up and running for at least 4-8 weeks BEFORE the water temps get to high above 45 or so. This time of year is when your filter is coming back to life, and you need to give it time to re-establish itself and the nitrifying bacteria that reside in the media. This can take a few weeks as stated depending on the water temps. The warmer the water, the faster the filter will cycle. Water testing becomes even more critical once you start feeding the fish for the season. As well, this time of year is when you can actually watch your filter come to life by testing the water on a regular basis. You will see the ammonia, nitrite, and nitrate levels rise as it is cycling, so once you see any of these given toxins, you will know what phase your filter is in with the cycle. This will really help as well if you do have health issues later in the season.
One of the other most common problems in spring are fungus problems, specifically Saprolegnia (Sap for short). This particular fungus is always present in the pond, but the only thing that changes is the amount of it in the water. It loves dirty systems, and it loves to attack fish that are in a weakened state such as the springtime when their immune systems are just coming back to life. Poor water quality like ammonia and nitrite and fluctuating pH will also promote the start and spread of this disease. This is why is it critical to keep up on the water testing in the late winter and early spring! It also shows itself more in the colder water temperatures of spring. This is not necessarily because it favors cold water but more because this is when the fish are the weakest and under the most stress. As well, this time of year is also favorable for water quality issues as the filters are just starting to come back to life. On top of all of this the parasites that live on the fish and in the water are also trying to attack the fish as well. So as you can see, this time of year can be very dangerous. This fungus can attack especially fish that have thin slime coats due to water quality issues or parasitic infestations. As a matter of fact, most Sap cases will be because of slime coat degradation from some other factor.
Sap appears as a fuzzy spot or patch and can appear on any part of the fish. Sometimes it is white to off-white in color, but there are times as well that it is green from algae growing on and amongst it. So look for it. It will require hands on treatment in most cases, and you will have to find out what if any other variables may have been involved. As discussed, poor water quality and parasites as well as dirty systems can all contribute to its appearance in the spring. You can read more detail treatment protocols on my website that will give the specifics of combating it.
If you can rule out prior springtime water quality issues, it will better help you diagnose any health issues you may have later on. You see, if fish are left in poor water quality in the early spring, this will allow the parasites to attack them even easier. So a few weeks to a month after the fish were in poor water for any period, this is when the symptoms from the bugs may show themselves. When trying to diagnose what is wrong with a fish it it very helpful if you already know for sure it was not from a prior water quality issue. This is why it is so import to test your water on a regular basis, and especially in the early springtime.
Parasitic infestations can also directly affect the health of the fish even if you did maintain proper water quality. This is why it is also critical to monitor the fish closely for symptoms this time of year. One thing to realize though is if you do discover a parasite or any problem that require any in-pond water treatments, you will have to wait for the water temperatures to be at least 55 DF before treating the fish. This is because most treatments will not work in water colder than that.
This is a good time to re acquaint yourself to the list of body language symptoms on my website. To read more details about water quality and spring health issues, please visit The Science of Water and Koi Symptom Diagnosis articles.
Written by John Fornaro, Hanover Koi Farms. ALL RIGHTS RESERVED BY HANOVER KOI FARMS, COPYRIGHT © 2017