Need help for wintering koi!

Background: With the summer purchase of my house, I inherited a koi in a very small pond (50 gal), and not knowing better, I bought two more small koi to keep him company. I didn't realize how fast they grow or how much space they need. They're all still fairly small, 6", 4" and 3" - so I'm hoping they can make it through the winter in this small space, until I can add another larger pond next spring. The PetWorld people keep assuring me all will be well as long as I keep my filter running, but the staff there are all so young (and pierced ;-) that I'm not sure I trust them to know.......

My question is about feeding. I've read all I could find about when to cut down, switch to wheat germ, when to stop feeding, but no place I've found has addressed fluctuations in temperature, and we have lots of fluctuations here in southeast coastal Virginia. The water temps have ranged from 45-65 degrees over the past month, changing often. Once the temps get down to the stop-feeding point, do I stop for the winter, or do I feed them whenever temps go back up? Once they go dormant, do they stay that way, or do they get active when things warm up a bit, only to go dormant again when it gets colder? I've become quite attached to them and hope to do the right thing.
Any help will be greatly apprecitated
Thanks
Liz

how deep is that pond , 50 gals dont seem like it will be real deep.
from what i have read , you would want at least 2 to 3 feet deep
so the dont key froze solid ..

how old is the pond?? Have the fish spend at least a full year in the pond, like going thru last winter in the pond. If they have then I would just keep the fountain going and don't feed them after the water gets to 55', their systems shut down until spring and the water warms up. Don't worry they won't starve to death, this is a natural thing for them almost like hibernation. My pond is 1500 gallons and I qiut feeding when the temp reaches 55'.Leave the water fall running all winter. And here in Michigan it gets cold, but after 6 years I have no problems

The pond is only about 18" deep. Not sure if the koi that was already here had ever wintered with his former owners, but I doubt it. They had only a small pump duct taped to a section of hose, and no filter. I got a filter rated for 500 gallons, so it's pretty strong; I hope it will keep things moving enough to prevent too much ice. I asked about a thermometer for outdoor ponds, but no pet stores around here seem to carry them. Do you think that would be needed to keep the water somewhere above freezing? I imagine I could find one on-line; I just can't bear the idea of inadvertantly killing my living creatures!
Thanks,
Liz

Hi Liz,
A couple of comments regarding the temperature and temperature swings. You'll see a chart below that shows what types of temperatures I see here in zone 4 (I apologize for the size of the file but it's necessary to get the chart resolution). The larger the volume of your pond the more the water temperature swings will be reduced or dampened compared to the air temperature. I've recorded the air temperature as well as the surface water, mid-depth and at the bottom of my pond (approx. 3000 gallons - 3 feet deep). So for your 50 gallon pond you may find that the temperatures will vary nearly as widely as the air temp. However, your fish should be able to survive those temperature swings since it's doubtful that even in your zone that you'll get a temperature drop say on the order of 15°F in 10 minutes! Even that would probably be dampened out by your 50 gallons.

There was a recent article regarding temperature and temperature fluctuations in a national Water Gardening magazine written by a veterinarian. Some of his suggestions were okay but one in particular I’m not sure I would use: putting a plastic insulation blanket (similar to ones used on swimming pools) on the pond at night to reduce drops in temperature. This would significantly reduce gas exchange as well as availability of oxygen.

While I don’t particularly care for heaters you could, in this instance, use the smallest livestock water heater you can find (the types sold in Farm & Feed stores used for keeping water troughs open during the winter). You would want to look for one that has a built in, automatic temperature shut off. If the capacity is too high (it is supplying more watts than you really need) you can run it through a device commonly called a “variac” and adjust the power supplied to the unit. Alternatively, if you know someone or if you are comfortable with a bit of wiring there are temperature monitors with built-in set points/shut-offs that you could also use to control the heater.

Come spring, yep, you’re going to want a bigger pond!! :-))

As to feeding the fish - I’d go with what has been mentioned above. I generally stop feeding when I know the water temperature is going to be consistently below 50° F. How do you know that it will remain that way? I usually check out the 7 day forecast to get an idea of where it’s headed. Of course up here our temperatures tend to head “South” in a short period of time! :-))

Thanks for the extensive information; very useful.
Liz

DRH2 - Thanks for sharing your temp data. This is the first winter (first time at all) that I have monitored my pond temp. It is a 2000 gal 3' deep pond. I have one remote sensor installed at 3'ft. We are experiencing below normal temps here. 13 as I type. I have one stock tank heater 1500 watt and one 300 watt deicer, the stock tank heater over the deepest part. I havn't mastered the software with this Oregon Scientific wmr628 system well enough to produce a graph yet. Its only been two weeks anyway. At 3' the temps have been consistently between 39.9 to 40.7, a surprisingly narrow range. I learned in another thread that the type of stock tank heater I am using (for the first time) has a high failure rate. While I have a backup ready to install I worry about the sudden drop in temp if it happens at night or while we are away. I do have the pond temp sensor on an alarm but you have to be here to hear it. Should I put the second heater in and at the ready without turning it on for a smoother transition? I have to admit that I worry all winter (this is my fourth with a pond) about cold temps and koi. I havn't experienced any winter losses yet, but I broke the bank this summer for two show koi. These darn fish are getting to me I think! We started with one 380 gal pond and a few goldfish. Fell in love with that. Then I got a koi by surprise for Mother's day two years ago. Just a pet store koi, nothing fancy, but he grew and he grew and he grew and well - one $11.99 pet store gift cost a 2000 gal pond with waterfall, new landscaping and a patio from which to watch him swim! Then of course we figured he was lonely and so on and so on and so on and now I have heaters and a temp alarm to keep him and his cousins toasty in February. Is this an addiction or what?

Snapple,
This ponding stuff's a hoot! Yep, it's addictive!! What I find interesting and fun is that you can have all kinds of ponds and get into it any depth you want (yes, the pun was intended!! :-)). I've seen ponds/water gardens that aren't much more than the bottom half of someone's plastic trash can up to things that just amaze me that someone has those types of resources to spend on a pond!! There's one fellow who's very much into the high-end Koi business that had a pond built into the side of his house (I believe it was on the order of about 18,000 gallons). In looking over just the pumping setup he had described I'd bet he's shelling out about $500/month just for electricity to run the pumps! Not only that, he runs the water through a reverse osmosis unit to remove all of the bad 'stuff' (having heavily filtered it prior to that) and then reconstitutes the water chemistry to try and mimic the waters found in the best quality Koi ponds in Japan. That is WAY over the top in my book. But you don't have to spend $$ just to enjoy it. Some plop the thing in the backyard and do nothing. On the other hand you can decide to educate yourself on the growth and culture of lotuses or hardy water lilies or Koi or Comets -- the list goes on and on.

Now as to the temperature - while I don't particularly like the heaters one of the real pluses is that if you lose electricity or your heater burns out getting another one into the pond is not that big a deal. Just plug it in and it will melt it's way into the pond! As to the “sudden” changes in temperature if the unit fails? If you check out my data you’ll see that I’ve had fairly significant swings BUT they occur over a day or two. If you had a fifty gallon bucket sitting on your porch then I’d be concerned with the temperature swings. But the more volume you have in your pond then the more water mass you’ve got to dampen out the swings so that they shouldn’t be too sudden. One of the problems I guess we all share to some extent is that we tend to anthropomorphize with our fish. Just remember they’re not warm-blooded critters! :-)). Have fun with your Oregon Scientific unit. I was using four HOBO data loggers that I dumped into the pond then retrieved after several months and downloaded the data. Just playing around and having a bit of fun.

Well since this thread is about wintering over koi, here's another question for DRH2: I've been using H2O2 per your instructions to keep the string algea at bay in the pond. Can I continue to use it in the winter? I keep my pumps going all the time since the pond is not going to freeze over in my zone. I don't want to add too much to the waste load in the pond and I didn't know if maybe the bacterial filtration slowed down with the colder temps. My Veggie filter is, of course, not as useful as it is generally is because all of the plants in it are dormant. But I still have the biofilter in the waterfall unit. What do you suggest?

Pixy,
Algae doesn't bloom in the winter, it turns brown and dies when the temperature drops. Also, since you aren't feeding your fish, you don't have the excess waste or decaying food to add to the problem. I am sure in your area all the trees have dropped their leaves by now also. So your pond will not increase in bacterial debris until everything starts thawing in the Spring. You do need to trim frozen plants back if you haven't, so they don't clog your skimmer or pump. I prepare my plants in late the fall by trimming the tops and lowering they potted ones in the water, that way they are protected. I don't have a de-icer here, but would have if I was in your area.
Sheila
edited to say...I don't use the H2O2 but wouldn't think it would be necessary since the string algae isn't forming now.

This message was edited Dec 14, 2005 6:42 AM

Well, that does make sense. After I posted I realized that all my string algae does look brown, but it hasn't let go of the rocks and floated to the bottom like it does when I use the H2O2,
I have cut back all the plants that are dormant. The water hawthorne is still putting out blooms, believe it or not. I know it likes cooler weather and goes dormant in the hot summer.
Given my zone and location, one would think that I would need a de-icer, but nothing ever freezes solid where I live. It's too close to Puget Sound. I'll be surprised if I even get any ice crust around the shallow end. It's been below freezing every night, but it gets above freezing generally during the day, and this has been a cold winter already! Plus my pond is about 4500 gallons and three feet deep. All my little fishies are hiding in their bottom caves now. But they come out when they sense that I am around the pond.
Thanks for the info, Shiela.