It appear the weather patterns through out much of the world seem to be changing. Winters are becoming colder and summers are becoming hotter. In California, over the next two weeks, we are preparing for some of the hottest days on record. Many are stocking up on bottled water and having their air conditioning serviced in preparation. We just wanted to remind our customers not to overlook the impact this heat might have on their koi ponds.
The two areas of major concern to anyone with a koi pond during a heat wave are:
First, make sure the temperature of the pond water doesn’t get too hot.
Second, make sure the koi will have enough oxygen to survive.
In both cases they are some simple and easy things you can do to increase their chances of surviving a heat wave and there are some more involved things you can do to prepare for the future in the event these extreme heat waves become a common occurrence.
-Water Temperature – Koi can handle a wide range of water temperature changes as long as the temperature change is gradual. They do fine in water from 40 to 80 degrees Fahrenheit. When the water approaches 90 degrees it can become very stressful to the koi. Much over 90 degrees and you are looking at the possibility of loosing some, if not all your koi simply due to the heat.
-Oxygen Level – Koi need a sufficient level of oxygen to survive. (See article) The problem is that as water increases in temperature its ability to hold on to free oxygen, which the koi need to survive, decreases dramatically. It is not uncommon for a pond or even a lake to have a large die off of fish at a water temperature of only 85 degree. (See news article) This is not due to the impact of the temperature on the koi but rather due to a lack of oxygen caused by the higher temperature.
Simple things you can do to control the temperature
In the event of a heat wave here are some simple things you can do to prepare you and your koi pond to better survive through the heat.
– Purchase a device to measure the water temperature. These can be very inexpensive and will instantly tell you whether you need to be concerned or not. (Website)
– If possible, cover the pond with a light colored tarp to reflect the heat from the sun. Keep it elevated above the water surface. Do not place the tarp on the water. All ponds need to breathe whether it is hot out or not. This can go long ways toward keeping the water temperature under control.
– If the water temperature gets to be over 84 degrees, and it is practical in your situation,
do a 30 to 50% water change. If the fill water is more than 15 degrees lower than the pond water try to refill the pond over a several hour period. If you are on city water don’t forget to add some dechlorinator to remove any chlorine before you refill the pond.
– Adding ice can be helpful on smaller ponds up to 2,500 gallons but is not very practical on larger ponds.
More long term solutions to control the temperature
Koi do well with some direct sunlight. Early morning is better than late afternoon sunlight which tends to be hotter. If you live in an area prone to hot weather and your pond gets a lot of direct sunlight you might consider the following.
– Build an arbor or install a shade sail over a portion of the pond. You don’t need to shade the complete pond all day long. If you can block the sun hitting most of the pond for half of the day you will probably be fine. Again, the afternoon sun is usually the hottest. (Maybe add picture)
– If you are building a new pond keep in mind that shallow ponds heat up very quickly. A pond 4 feet deep or deeper adds volumes to the pond causing the temperature to be much more stabile.
Simple solutions to provide more oxygen
– If your koi start gathering around the waterfall or are at the surface gulping in air you have a serious lack of oxygen. You need to act immediately.
Simple things you can do to increase the oxygen level
– Check the water flow of your pond. Make sure it is not slowed down due to a plugged pump basket or filter.
– If you have an air pump, install the stone into the deepest part of the pond and turn it on.
– If you have a submersible pump, set it up so it will pump pond water up into the air and then fall back into the pond.
– Attach a garden hose to a chair or ladder so the hose is several feet above the pond water level. Turn on the water so that it drops down into the pond drawing air with it. (Caution: If you are on city water and don’t have any dechlorinator to neutralize the chlorine in the water don’t let the water run for more than a couple of minutes.)
– As a last resort you can use a bucket to gather pond water and lift it up before pouring it back into the pond. This can be very helpful but not practical long term.
More long term solutions to provide sufficient oxygen
– Installing a waterfall is a great source of oxygen for any pond.
– Installing jets can also provide oxygen to the pond water.
– Installing a serious air stone (not an aquarium air stone) can go a long ways toward preventing a serious lack of oxygen. Air stones have their draw backs because they can create a lot of disturbance to the pond surface. If you have it on a switch then you can turn it on as needed. Keep in mind that if you don’t run it often enough, when you need it, you may need to be able to draw it to the surface to scrub it clean from algae before it will work. (Website)
– Probably, the best all encompassing protection against lack of oxygen for you’re koi is the Advantage O2 System. This system is designed to keep the pond dissolved oxygen level at a very high level all year long and under any circumstances, even during an extended power outage. (See website)
We all love our koi. Few things can be more hurtful than loosing even one of our beloved pets to an event that we might have been able to prevent. We hope you will take this alert to heart and look closely as to the effect these heat waves might be having on your koi.