First, get the net and get those leaves out. Decaying vegetation will stress the fish a lot more than the temporary stress of seeing a net. It will also add ammonia and excess nutrients to the water and provide a bed for bad bacteria to grow.

Whether or not to leave the pumps running is kind of tricky. Some do and some don't. If there is a risk of the pipes freezing, then by all means shut them down. We get cold here, but not as cold as, say, the upper states and Canada. I always leave my pumps running with the filtration going. It does make the water temperatures colder, but I have never lost a single fish during the winter, not even the babies. IN your zone 9, I would think the benefit of leaving the pumps on would outweigh any negative effect of cooler water.

Winter is a stressful time for our wet pets. If you're losing fish at a water temperature of 44, then I would check the ammonia level first. If the ammonia is up, turn the pumps back on and add an ammonia binder until you can do a partial water change.

Thank you so much for responding. I will go out and remove the leaves as soon as I type the last word here.

The small fish that died was in the upper, shallow pond. I'm not even sure it's 2 feet deep up there. There was another bigger baby up there & I moved him into the big pond. That fish was so happy!

The boss (I'll say no more.) decided to put the pond on a timer. He had the pump running during the day and turning off automatically at night. I asked him to shut it down completely because of my concern about cold water being dumped onto the babies. When the pump starts up in the morning, the water level in the lower pond (where the babies are) drops about a foot. Should I add more water every morning to bring the water level back up? We have well water so it's not a big deal adding fresh water.

I don't think we'll have to worry about the pipes freezing where we live. After reading your comments, I think running the pump is the thing to do. Thank goodness we shouldn't have many more weeks of this cold.

Also, I will test the ammonia level to be on the safe side.

Thanks again, nancym1956. I'm off to net some leaves.

I think leaving the pump going is the better choice since ice is the only real reason to turn it off. Baby koi are still cold water fish. To my surprise, my pond is still not iced over since I didn't turn the pump off this season. I normally would have 3 or 4 inches of ice on the pond. If you must turn off the pump, get an air pump(bubbler) to keep the oxygen level up which helps with the ammonia levels too.
If you are going by air temps, you don't really know what temps in the pond are like. You can get a remote, waterproof thermometer for the pond at most hardware stores starting at about $25.00. Knowing what the temperature is 2 feet down in the water is a lot better trying to go by air temps. Air temps change a lot faster than water temperatures.

Nancy is right about everything she wrote.

Okay, the leaves are out, the pump cleaned and everything is up and running again. To my surprise, I only netted 1 baby during the process. The water isn't very clear anymore but I can still see my little babies swimming all around. Indeed, I believe they are happier and that's important.

Jim checks the water temperature with his infrared thermometer that has a little laser thingy. Yesterday, I put the pond thermometer back into the water. This morning it was 41°F around 7:30 am.

In the past, we've always kept the pond running 24/7. Now, it's on a timer along with the hot water heater (another story). Anyway, I will only concern myself with the things I can control.

Oh, somebody in an older thread mentioned, "learning the hard way", in reference to the UV light in the bio filter during the winter. Should I add that to my list of worries? LOL We just purchased a bigger pump and bio filter last year.

Nancy & Sleepless, thanks again for your input. We've had the pond for almost 10 years; however, this is the first time that we've attempted to save any of the small fry.

Bon

I bring my UV in for the winter, but we probably get quite a bit colder here than you do. However, the bulbs don't last very long, so I doubt that it's working anyway.

Bon,

I assume that the reason the pump is on a timer at night is because of cost of running it. What I might suggest is that you might want a small pump that uses very little power that would run the pond during the winter 24/7 and still save money. The other thing that you might want to tell the "boss" is that turning the pump on and off each day is going to shorten the life span of the pump.

I am friends of a pond contractor in the Atlanta and one in Savannah and I know they both recommend to their customers that they run their ponds all winter because the winters are mild enough there.
Mike

I am in upstate SC about 4 hours from you. I am in zone 7b which is a little colder than you guys in Savannah.
I leave my pumps and filters running 24/7.
I do clean my pond in the fall and spring to remove leaves and dying vegetation.

I wasn't sure what I'd do when winter set in, but I have been running my pump 24/7. It helped keep a hole open in the ice when it got really cold here a few weeks ago. We have been having an unusually cold, wet, and snowy winter here in Oklahoma. I can't remember the last time it snowed this much. Been many a year, that I do know. I am so ready for spring.

Mike, "BINGO", it's all about the money. I'll do some research in reference to more energy-efficient pumps. Our spare pump is about shot anyway and should be replaced. So, that solution should be doable. Good idea!

Nancy, I didn't know the UV lights didn't last long. Our filter is above ground but is almost completely surrounded with thick landscape stones with a cover. It's also located under our breezeway that connects the house to the garage. Don't think it will ever freeze but it's good to know that we should keep an eye on it.

Lsst, in the past, without fail, I've always thoroughly cleaned the pond in early spring and in the fall. In addition, I'm usually on leaf patrol all year because we have huge trees. Some that shed in spring and some that shed in the fall, so, there are always leaves to contend with here. This September my mom was ill and I spent 4 months in middle Georgia. Honestly, when I returned home and saw the pond, I was surprised ANY of the fish were still alive. The boss is excellent at building things and the technical stuff; however, if the water is clear, the boss thinks the pond is clean & healthy for the fish. I've been playing catchup ever since my return.

Hardin, if I had that cold and snow to deal with all winter, I'd be a nervous wreck. I did live in NJ for 3 years in the 80's and every winter there...I WAS A NERVOUS WRECK!

Thanks again, everyone. I'm always learning around here.

Bon