The Importance of Performing a Springtime Pond Cleanout
Springtime is always the season when our fish have the most problems, especially when coming out of a tough winter season. One of the primary reasons we see more fish health problems in the spring is due to the fact that the fish's immune system is virtually non-existent as they come out of the state of torpor of the cold winter water temperatures. This combined with the fact that all the pathogens come to life a lot sooner than the fish's immune system during this warming in spring, can be the straw that broke the camel's back. This is the time that the fish are most vulnerable to attack by these pathogens. For this reason, it is critical to maintain superb water quality and inspect and watch the fish closely for signs of ill health. Look at the Diagnosing Koi Symtoms page for info on identifying health problems in Koi.
As the water gets to around the low to mid forties, you will see the fish start to become more active. Remember though, do not feed them until the water temps are at least 50 DF and holding, and even then start off with very light feedings and not every day. The weather and exact water temperatures will dictate how much and how often, but just remember to keep it light. You do not have to ever worry about them starving as there is plenty of natural foods in the pond to keep them alive, and Koi can go a long time without eating - weeks even, and in cold water, even months.
Spring is also the best time to clean the pond and filtration systems thoroughly, as the filters have not yet begun to cycle and grow the nitrifying bacteria to any great degree. So, this would be the time to tear the filtration down and give it a good cleaning and do any improvements. As well, this is the time to clean the entire pond, even to the point of completely draining and powerwashing everything which I would highly recommend. One reason is that it will be much easier to temporarily house the fish outside the pond in some type of pool or tub and not worry as much about oxygen and water temperature variances from the new pond water to the tub water.
If you do decide to do these cleanings, make sure you have an appropriate temporary housing for the fish while you do it. Kiddie pools, large tubs and so on are fine as long as they are the appropriate size for the number and size fish you have. A minimum of 200 gallons will usually suffice, but the bigger the better. I would also suggest they be filled with the water from the pond that the fish are coming from as you will not have to worry about acclimating them to new water at that time. As you fill the temporary system with the pond water, it will make catching the fish much easier and less stressful as well. I would wait until it is almost empty, and then catch and relocate them to the temporary systems. Make sure to cover their temporary home with netting or something to keep them from jumping out. I cannot stress enough how secure and strong this cover needs to be, as these fish can be very forceful at times, and they will most likely try to jump out. This covering is a must. You don't want to find them on the ground dead because you did not secure the cover properly or did not have one at all.
Most ponds can easily be cleaned in a day, but at times it may take another day or even two to refill the ponds due to their size. In these cases when the fish will be in these temporary homes for more than one day, you will absolutely have to test the water, and have salt and ammonia binder on hand for the spikes in ammonia and possibly nitrite that might occur. You do not need filtration, but you should have some sort of areation for sure. Also make sure to have these temporary systems put in a shady place so the water does not warm too much in the sun. Remember, the goal is to keep the water in these systems as cold as the new water will be when you refill the ponds. This will make re-acclimation to the pond a much easier and safer task. Also, do not feed the fish whatsoever while they are in these temporary systems. NOTHING AT ALL, as it will only promote more ammonia spikes.
When relocating the fish to these temporary homes it is also a good time to give them a thorough inspection for signs of problems like parasites, ulcers, fungus and other issues they may have. If there are any issues like these that require any topical treatments, wait until you are ready to put them back into the pond before applying any of these treatments. As well, if you think they will require further treatments, then you may want to consider putting them in some sort of cage inside the pond so that you can easily get them again to apply the treatments. Then once you feel they are getting better you can release them into the pond.
Your goal during this whole process is to try and keep the water in the temporary system from getting any warmer than what the temperature of the water will be in the pond after it is refilled with new water. If you can keep them within ten degrees of each other that would be good, but the closer they are to each other the better it is. It is more difficult to acclimate a fish from warm water to cold water than it is from cold water to warm water. So if you allow the temporary system to get too much warmer than the pond will be after it is refilled, the more difficult and dangerous it will be to re-acclimate them to the pond. This is why it is best to do this cleaning in the spring while the outside temperatures are still chilly. If you attempt this in the summer the temporary system will most likely get very warm, then you will be left with trying to acclimate the fish to the newly filled pond which will most likely be cold.
In general, the sooner the pond is cleaned in the spring, the better it will be for the fish. They will have less issues with pathogens in the newly filled pond that is free of any muck and what not. As well, if for whatever reason you may end up having to treat your fish due to springtime pathogen attack, then the treatments will be much more effective in the cleaner water that has less organics and muck to bind the treatments. When treating fish in dirty or high organic water, the treatments end up getting absorbed by these organics and therefore never make it to the fish to kill the bugs.
Written by John Fornaro, Hanover Koi Farms. ALL RIGHTS RESERVED BY HANOVER KOI FARMS, COPYRIGHT © 2017