Koi San's Corner
Koi San's Corner Entry for Oct 25, 2009

Hi Everyone;

Fall is upon us now and winter isn't far behind. In this blog entry I'd like to discuss the fall / winter season and some things you can do to give your Koi the best shot at overwintering, and emerging healthy in the spring.

As the water cools it's important to remember to pare back on the food. I go to an every other day regimen until the water dips below 50 degrees. Then I stop feeding all together. There are stretches during the fall that the days are warm and beautiful. Pond temperatures can briefly rise above 50 F and then soon fall back. During these warm periods you may find your Koi begging to be fed. Here's what I do under those conditions: First, check the weather forecast. Forecasts today are very good at looking 3 days out. If the weather will be warm for an extended period of time, and the water Temp has risen above 50 degrees F, I will feed them. Just give them enough food until they lose interest. That happens quickly in the colder water. I will continue to feed them until I see that the weather will turn colder in 3 days. I like to have them fast for at least 3 days before the cold snap. This gives their system a chance to clear the food from their gut. Any food that remains in their system after it gets cold can rot and cause health problems through the winter. I always err on the side of caution here. A few more days of fasting in the winter is not as bad as filling them up with food when the water is cold.

The second thing is to clean them of any parasites. Parasites seem to thrive in water temps lower than the immune systems of the koi. Putting them to bed clean for the winter has paid off for me. I use Terminate for 3 days and then add the Parazi on the 3rd dose. Terminate has formalin in it and should not be used when the water temp is below 50 degrees F. If the water temps in your area are under that, you may still use the Parazi as a stand alone. This has no negative effect in the cold water. This will at least wipe out all the flukes.

The third "must do" is shutting off the waterfalls. Cold air can "super cool" the water in the winter and running waterfalls will exacerbate the issue. There's also the issue of ice dams causing waterfalls to redirect water outside the pond. I leave my bead filter running but redirect the return water pipe to the pond about mid level. Too deep, and it can disturb the warm water at the bottom. In a 4 ft deep pond I place the return at about 18 in. deep. I also have an air stone running to put oxygen under the ice. There again, I keep the stone in the shallow water, near the edge, so as not to stir up the warm water below.

Another regimen I use yearly is salt. While some people believe in keeping a low dosage of salt year round I do not. Salt was once one of the Koi keeper's best medicines until the parasites we seek to kill, got resistant. Low concentrations of .3% salt (roughly 3 lbs per 100 gal.) constantly only make the organisms more and more resistant. I do use salt but only once a year and I use it in higher concentrations. In December when all my plants are dormant I add a bag (or bags) of pure salt to my pond. I usually buy water softener salt in 40 lb. blue bags from Lowe's or Home Depot. Make sure you use the pure salt and not the one with additives for iron or rust. These are not good for your fish and usually come in a yellow bag. Check the label first before you buy. I bring the salt level up to .5%-.6% gradually over a 3 day period and let my weekly water changes slowly lower the concentration throughout the winter. The salt will kill some common parasites at this level but it also helps regulate the Koi's osmosis (body fluids). It cuts down on winter stress and I find it effective if used once a year. Do not use salt in conjunction with Terminate or other formalin products. When salt is present at more than .2% it is wise to avoid the use of Terminate. It can cause burning of the gills. When I use salt the water temperature is generally under 45 degrees so Formalin is really not an option at those temps. I highly recommend the use of a salt meter to get an accurate reading. Koi can tolerate salt concentrations of .8% or higher but it is not wise to go over .6% in your pond.

Finally, there's been a breakthrough in the development of cold water pond bacteria. I use Medzyme dry when the water is over 50 degrees, but Koi keepers have had little choice in lower temperatures. This fall the Aqua Meds folks have come out with a new product specifically designed for Koi ponds in the colder climates. Arctic Blend is a product that contains helpful bacteria from the Arctic Circle. This bacteria has the ability to produce their own anti-freeze and they work well in water down to 35 degrees F. (Read about it here.) I will be using this all winter on my outdoor ponds and Koi San's Korner will dedicate a Spring Blog 2010, to share my results.

That's it for now. I hope you find this helpful. I wish all of you, and your "Living Jewels", the best of the Holidays.

Regards Koi - San Regards,
Koi - San