Fall Weather

The leaves are falling and the raptors want to bulk up for the long flight south for the winter. I had some kind of raptor, possibly an owl, make an aerial attack on the upper pond one morning. I heard an owl type hoot just before sunrise though it could have been anything. When I went out I found part of my leaf net had been ripped at a tie down but it held. In the center was a lonely feather. Looked like a down type feather. The koi were fine. I suppose the scream of defeat is better than silence and the alternative.

Now that the leaves are falling and birds are attacking, I've come to realize that the cheap econo nets we all buy to keep leaves out are just too thin and cheap. Do yourself a favor and buy the deluxe nets. They cost a bit more but are much better at warding off a diving hawk or a blind heron. Try not to let them float on the water. It's best if you can keep them tight about 12" off the water. If they float, the koi will be pushing them up to search for food and they will abrade the nose and scales. You will want to keep them down tight around the edges with rocks or bricks. I've found a slant to work well 12" to 24" high along the back hanging down and anchored at the rear and slope to the front of the pond and anchor with rocks along the sides and front. This makes it easier to get rid of leaves as they will tend to accumulate near the front bottom or the wind will just blow them off the net.

Simple wooden poles or 1x2's hammered into the ground in back of the pond should be enough to hold it elevated. It's important to make sure there are no openings. First you want to keep out as many leaves as possible and you also don't want a bird or squirrel to get trapped inside and not be able to get out. No openings at all. Leaves will find a way in if you have even the smallest hole.

The sick koi have been doing well. I've left the salinity in the QT pond at .3%. Nitrites are a little high but the salt will detoxify it...for a while. Hopefully the filter will mature before I need to shut it down. If not I will transfer a media bag from the lower pond waterfall to the upper filter and let it run for a week or so until nitrites are zero. When I cleaned the upper pond, I also cleaned the filter due to parasites so it had to mature all over again. Fortunately I have media from the other pond I can use before winter sets in. This is one of the reasons why I have two pumps and two filters and now two ponds. Always, ALWAYS have a plan B when it comes to Koi keeping.

Real World Example

I used the below method to calculate the volume of my top pond.

0.28% change = 2.8 Parts per thousand (PPT)

(17.5 lbs of salt / 2.8 PPT change ) X 120 = 750 gallons

Close to what I expected but I was still off by 200 gallons. That's a lot, about 25% off or so. That would easily make a difference if I were to dose the pond with meds while fish are in there.

It's very easy to over estimate capacity and put your fish at risk. Always know your pond capacity for emergencies.

Pond Volume Calculation

Not many of us can afford a gallon flow meter to connect to our water supply when filling our ponds. There is another way to calculate the volume of water in your pond by adding salt. Koi are very tolerant to salt it seems and it has a lot of benefits. The salinity range should be about 0.1% to 0.3% as a long term bath but you can increase it to 0.6% for several days, 0.7% for about 1 day and even carefully up to 0.9% for about 10 minutes to kill parasites, bacteria and protozoa. Don't leave your fish in water over 0.3% for months and months. Parasites will grow resistant to salt and next time you will have to treat with a higher concentration.

Benefits of Salt in the Koi Pond

• Increases protective slime coat - 0.1% - 0.3% concentration
• Aids in absorption of oxygen through the gills - 0.2%
• Will kill many forms of parasites and protozoa - 0.6% or higher up to 0.9% (Carefully)
• Increases Koi's buoyancy making it easier for them to swim
• Decreases osmosis in the fish so their kidneys don't have to work as hard
• Slightly decreases the freezing temperature of the water allowing it to absorb oxygen easier during the winter by reducing ice buildup.

You will need to buy a salt meter that can measure salinity in % or Parts per thousand (PPT) up to 1% and you will need to buy a 40lb bag or two of Solar salt used in water conditioning systems. It's better to completely dissolve some of the salt in a bucket with some pond water. Solid salt can burn gills and fins and if not completely dissolved its easy to overdose your pond possibly killing your fish.

The formula as a starting point is that it takes 1 lb of salt per 100 gallons of water to raise the salinity to .12%. So if you "Think" your pond is about 1000 gallons you will need 10 lbs of salt to bring it up to .12% salinity. Well we don't know the volume exactly but the above will let you know how many bags to buy to get to the desired salinity level.

So to calculate volume you use the following formula:

V=(P/C)x120

V=Volume in gallons
P=Pounds of salt added
C=Change in salinity in PPT (or 10 times the % change)

For example,

I think my pond is about 2000 gallons but I'm not sure. Using the salinity tester measure the salinity of the pond before you start. In my case it was 0.0%. I measured my bags of salt on a bathroom scale and found them to be exactly 40 lbs each.

Slowly dissolve about 1/4 of a bag at a time into a 5 gallon bucket of pond water and using a small aquarium pump, circulate the water until it's all dissolved. Then pour it into the pond around the edges but not directly on your fish. Do this three more times until the entire bag has been dissolved. Let the water circulate through your pond pumps for a while and after a few hours or even the next day, measure the salinity of pond.

In the example I used, I dissolved the entire 40 pound bag. The change in salinity was 0.29%.

So using our formula, V=(40lbs/2.9)x120 = 1655 gallons

Wow, I was off by about 350 gallons!

This is important to know when and if you ever have to dose your pond with medication. An error in the dosing could cause you to overdose and kill all of your fish.

You can salt the pond slowly over time but you have to weigh the salt you put in each time and add it all up when you are done. Don't add water or you will mess up the calculation. Always use pond water to dissolve the salt.

Salt will not evaporate so to reduce the concentration you will need to perform water changes. Concentrations over 0.3% should not be pumped into your lawn. You will have to pump into your toilet and let the sanitation company deal with it. Also remember that two 0.3% water changes are additive to your lawn and could kill your grass. Make sure you water your lawn real good before the second one or wait until after it rains.

Salt is cheap and beneficial to your Koi and at small concentrations of 0.2% or less can be used year round to help your Koi ward of bacterial infections and absorb oxygen easier duirng cold winter months or during the hottest of summer days.

3 Koi Released into the Pond

Tonight I released the 3 Koi that were sick in QT for the last 10 days.  All signs of infection are gone and they have been eating.  I released them into the upper pond just in case and they will stay there until next year.  I am salting the pond slightly to help them build up their slime coat and get adjusted to being outside in the cold.  Water temps have dropped to 65 degrees.  Hopefully they will survive what winter throws at us this year.

Upper Pond Cleaned and Filled

Yesterday I cleaned out the upper pond and reset some of the stones along the back edge which had fallen and become unstable. I sucked out all of the muck with a shop vac then filled with water.

Today I rinsed off the plants put them back in the pond and then treated with a strong dose of Potassium Permanganate. No fish in there yet so I doubled the recommended dose. 5 hours of treatment and I will deactivate it with hydrogen peroxide.

Tonight I will oxygenate the water and put a fish in. I still need to slowly bring down the temp on the QT tank to this pond's temperature.

Almost Done

I'm at the last two days of treatment. The meds are finished and now they are soaking in .2% salt water. Sat and Sun to go at 86 degrees then I will work the temp down to pond temperature. They are doing very well. All fins are out and clear and they are chasing bubbles at the surface trying to eat them.

Tomorrow I will pump out the water from the upper pond and see if I can get it cleaned up and new water put in. Hopefully Sunday or Monday morning I can Zap it with Potassium Permanganate and get the fish in a few days later. Need to bring the temperature down slowly to match the pond water temperature.