October: Think Winterizing
By Nancy Moore
Today the afternoon temperature is 53 degrees here in chilly Bothell. We have more sun coming up, but the Luna Park goldfish pond is now at 52 degrees, which means that I will likely stop feeding by this weekend and by next weekend for sure. Now is the time to head for the hardware store and load up on insulation and heat tape for your pipes, valves, ballasts for UVs, etc. I plan to get a large roll and a 5-6 inch roll at McLendon’s as well as some insulation tape. I want to be more prepared for possible cold weather. Remember the 11-degree F. temperature we had in January 2024. Koi ponds all over the area had pipes that burst and valves that split. Brass valves are particularly vulnerable. Here, one of my Kozy Koi heater lines froze in a small covered but not insulated area, which caused havoc then and I have now found a second leak and have had to disable one of the heater coils. The key here is not to wait until it gets cold. Be ready! Even though we may have some sunny days ahead, if you wait until cold is predicted, you can count on hardware stores being out of everything you need!
Here are some tried and true reminders about what we as koi keepers with outdoor ponds must think about. Many of you know all this information, but we have new club members, so let’s review what needs to be done before really cold weather, wind, sleet and snow, hit us. Keep last January in mind!
As winter approaches, it is ideal to have on hand:
- A generator for when the power goes out so we can keep air pumps, pond pumps, and filters going and an instruction booklet for how to use it.
- Gas for the generator unless yours is operated by natural gas or propane.
- A pond de-icer.
- ClorAm-X or Ultimate to gobble up ammonia if something happens to our filter.
- A back-up pond pump, just in case.
- A back-up air pump, just in case.
- De-chlorinator, like Harmony, Sodium Thiosulfate, ChlorAm-X, or Ultimate for use with water changes.
- Appropriate crystal solar salt, no additives, 99+ % sodium chloride.
- Baking soda (bicarbonate of soda), so that the KH level can maintain at 80 ppm or higher all winter. I keep my outdoor pond around 100 ppm so I don’t have to deal with pH swings during dark, gloomy winter months. Remember that filters and fish use carbonates all the time, so the KH level must be maintained.
- Insulation materials.
- Heat tape.
- Tarps to blanket vulnerable sections of the plumbing.
Before winter gets here, get the muck and debris off the bottom of the pond. This is crucial. Vacuum it or call a professional to clean your pond. It may be too late to contact someone else now, but we can clean out a lot with debris nets. I got mine at Aqua Quip and it works great. I personally have a pond vacuum that works well, called an Oase Pond-O-Vac 4. It is very effective at pulling algae, needles, leaves and crud off the bottom. Fir cones jam it up, so I try to scoop those out first with my debris net. Before the cold hits, we should strive for a mulm-free pond bottom. I don’t need to pull out my water hyacinths now because the raccoon family polished them off last week. But if you have water hyacinths and water lettuce, you do want to pull them out before they dissolve into goo. Winds have already blown leaves and needles into the goldfish pond, so there is a lot of debris to vacuum, and, of course, the skimmer now needs to be cleaned out every day. If it is possible in your situation, put up bird netting to keep leaves from falling into the pond and sinking to the bottom. In the Luna Park goldfish pond, this is impossible, hence the Oase Pond-O-Vac.
Now is a good time to cut back pond lilies and remove the decaying foliage. Chris Moore, of now defunct Moorehaven, always argued that fall was a good time to pop a fertilizer pellet into each lily pot, arguing that the water was warmer now then it would be in the early spring. In my pond, this is difficult to do so I probably will wait until Spring.
Rinse filters before the onset of Winter; pond water is best, but the late Spike Cover indicated that the filter bacteria can withstand tap water with a hose sprayer. A filter caked with muck and debris does not nurture and cultivate the appropriate “good” bacteria one needs to handle ammonia and nitrite, even though we are going into lower temperatures. A dirty filter now will be way dirtier in the Spring, when parasites really perk up and start to multiply, and when we need the filter’s bacteria to multiply. My task this weekend is to remove all the media from the 300 gallon tank and hose it off and spray out the two inches of mulm at the bottom—good fertilizer for nascent plants that will emerge in spring. This is a filthy job but it has to be done. If I had a bead filter on the goldfish pond, it would not be time consuming and icky—just flip a switch and turn on the pump. However, I have J mat media in bags.
If test kits are out of date, get new ones. Look at the bottles in the store to see what the expiration date is…. some test kits in pet stores have been sitting on shelves for a long time. And when you test, remember to really shake each bottle first. Make sure you have a KH (carbonate hardness) test kit so you can make sure you avoid pH swings during the winter. This is crucial especially during cloudy and dark days, typical of the months ahead. It is helpful to read the directions on how to use the KH kit so you don’t get confused about blue to yellow (API kit).
If your only return is a waterfall, think now about adding pipe and a valve so you can run your return water back to the pond under the surface and then shut off your waterfall. There is still time to glue in valves given the temperatures next week. Should we have a major freeze, and your waterfall freezes, it is possible for your pond to empty itself all over your landscape.
Another handy item is a horse trough heater or floating pond de-icer. Check with your local dealer or Amazon or Webb’s. On my pond, the two winter returns are under the surface of the water, so that keeps an air hole open. We want gasses to escape should the pond freeze over, so an air hole is crucial. I hope we all know that taking an axe to whack open a hole in the ice has repercussions for our fish. Don’t do it.
Many of us stop feeding when the pond water in the morning hits 50 degrees. This is a good general rule. Some koi keepers may experiment with feeding tiny amounts of food during the winter; novices should probably not do this. Remember that a koi has no stomach…. just a long gut. Koi are temperature dependent, so everything really slows down when it gets cold. We don’t want a big wad of koi food sitting halfway through the gut if the air temperature drops to 16 degrees and the fish are in torpor for 3 weeks. That said, some club members have been experimenting with feeding Kenzen in small amounts during cold weather all winter. Tiny amounts—if koi are interested.
Heavy salt is another way to super chill our water. The only way salt leaves the pond is through water changes. So if for some reason you have treated your pond with salt, that needs to be reduced down to say .5—1 ppt before freezing weather. If someone told you your pond needs salt for winter, think about it. Why would you need salt? What your pond does need is a carbonate level (KH) at 100 ppm or above.
Continue to rinse or backwash filters through the winter and do small water changes to refresh the water and rid the pond of fish pheromones.
Look at the koi closely. If there are any problems, deal with them now. The water may still be warm enough for fluke treatments or other parasite treatments. For example, Pro-Form C, which I happen to use now and then (good for trichodina, chilodinella, Ich, costia), requires water temps of at least 52 degrees F. and a salt level under 1.5%. Praziquantel, on the other hand, which is a fluke treatment, can be used at any temperature and salinity isn’t an issue (according to the compatibility chart at Koi Care Kennel). If your fish do not have flukes, don’t treat for flukes. Scrape and scope first.
Our goal as koi keepers is to have the fish emerge in the spring as healthy as they can be; they will be less likely to have disease and parasite problems if they are overwintered in a clean pond and if we continue to pay attention to water quality.
One other thought: If you have a standby generator, like we do, and if you leave on vacation, you’d better brief the house or fish sitter on its basic operation. If and when the power goes out, if someone is living in the house, make sure they know what to unplug so the generator doesn’t overload.
Winterizing that we all do now will pay off once we roll around to spring.
P.S. No one ever said koi keeping is cheap or easy.