I am assuming you have a submersable pump. Unplug the pump and pull it out. Remove the intake hose and the protective ring around the impeller. See if there is any debris caught in the impeller. Make sure it rotates easily. If it does not, Pull the impeller straight out and remove the thread or hair or plant material that is wrapped around the impeller shaft. I have had to cut some of it out and the really fine stuff is hard to see. I suspect the very long blond hair I found in the impeller was carried to the pond by birds or else we have mermaids. It is not likely there is any debris in the output hose but check for a pinched or kinked hose. Put the impeller back firmly. Keep it straight and make sure it rotates easily. Put the protective ring back over the impeller. Reattach the input hose after making sure it is clear of any debris or kinks. Even if you did not find something blocking the hoses or impeller you have done a routine maintenance that needs to be done several times a year. Put the pump in the water and plug the pump back in. If it doesn't work now, you probably have a damaged or burned out pump but I guess it will work just fine. We would enjoy seeing pictures of your pond. Sandy

Fish produce ammonia. Ammonia is toxic to fish. It is also uncomfortable so that might cause them to jump. Fish poop, excess food and organic waste rotting on the bottom produce nitrites and toxic gases as well as being a home and nutrient source for anaerobic bacteria. That may not cause them to jump but it is unhealthy for the fish and for humans. (You might like the link below.) Ph is affected by many things including rain, organic matter etc. Koi do not tolerate water that is too acidic. They do much better in alkaline water. Nitrites and nitrates in the water will cause water problems and feed algae. KH is a measure of buffering capacity or resistance to change in PH. Knowing the levels of these is important to avoid a crash that can and will kill fish.That is where a test kit comes in. There are 3 types. The first is a research grade kit and while extremely accurate it is expensive and you don't need that level of results. The second type are strips that come in packs of fifty, are easy to use and can be frustratingly inaccurate unless fresh, properly stored and kept absolutely dry until you use them. Most of the ponders on this forum don't use them although a few do. I tried them, didn't like them. Half of what I bought were not accurate. The third while not as accurate as the first is totally adequate for your purposes. It contains liquid chemicals, test tubes color charts and instructions for the tests you need to do regularly. They run around $25 to $30. It is recommended that they be replaced each year but I have cheated and had good results when the kit was carefully stored. I don't push it though. It is not worth it to me if I lose a koi because of it. The next part is from a web site but is correct. "When to test. An established pond with healthy Koi fish should be checked every month. It is only when you notice something out of the ordinary, and possibly during seasonal changes, that an additional test or two might be prudent. An ounce of prevention is worth a pound of cure. A simple test, at the right time, can prevent a minor problem from becoming a catastrophe. When starting up a new pond system, daily tests may be required then weekly for a couple of months until the system has stabilized." Right now your main concern should be ammonia. You have a lot of fish. Limits on the number of fish is usually figured by gallons of water to inches of fish. Since some of your fish are rather large you may very well be approaching the edge of disaster. The test kit will tell you. To reduce ammonia, you can aerate with a bubbler, agitate the water as with a waterfall or fountain or use a product to remove it chemically (I use a combination of Ammoblock and Activated carbon in a bag in the Skippy filter. It does a good job for my little pond) In any case, you need to test the water. Here is a link that might be useful: Ron's Pond Scum

Hey there. In zone 6a you shouldn't have a problem with running the pump/bio filter all winter. I'm in zone 5 and mine runs all winter since I got up the courage to try it. But, and it is a big but, a lot depends on the size and depth of the pond, the size of the pump and how cold it gets. One of the smaller ponds I built that was shallow (18 inches) and only held 150 gallons froze so badly that the tubing froze closed and almost wrecked the pump and since the water was pumped onto the top of the ice and couldn't get back under it, there was no water left under the ice to pump which wasn't good for the pump either. At the same time a larger pond, 1000 gallons, 3 ft deep with water running through a large Skippy filter made lots of ice but the falling water created a tube where the water was moving too quickly to freeze. Rather pretty. The surface area there is about 10x10. I also run a bubbler 24/7. No other deicer has been necessary. The pump volume is about 1570 gallons per hour. If you have 25 fish your pond is probably at least 1000 gallons so if it is not extremely shallow and your pump is adequate, you probably won't have a problem. If you have to choose between a pump and a bubbler take out the pump. So long as the water continues to be aerated the fishes will be fine. Algae does not grow in really cold water so you could take out the UV. Don't leave it in if it isn't running or the tube could shatter from the cold. The muddy water on the bottom is probably mulm (poop and organic debris settling to the lowest level. If there isn't a lot and your water is otherwise clear and healthy (test the water)you can leave if for now. Vacuum it up when the weather is warmer or move the input tube closer to it now. Is there some reason you can't allow the water to drain over the side or out an overflow tube? In most cases, unless you have a real gusher the water level should not get so high to cause a lot of overflow. It seems a lot of trouble to lower the water level before a rain. Usually there has been enough evaporation to drop the level and the rain just tops it off. The only reason I can imagine is if the pond is not above the surrounding ground level. Then you might have a problem with runoff going into the pond and that is something you need to avoid in the first place.

Sorry it took so long to get back to this but my free electrician (brother in law) keep pushing back the date that he would come over and run the tests. 1. What is the pressure reading on the filter gage. Normally this should be between 12-25 psi...higher pressure is a sign of too much restriction between the pool and the pump...lower pressure is a sign of suction line restrictions. Both cause the pump to work harder than normal and the motor to overheat because it's not operating as designed. Pressure is right at 10 psi after backwashing and I clean it when it reaches 18 psi. It is currently at 12 psi. 2. Are there any bubbles observed when looking through the clear basket lid..if bubbles are observed and the pump is producing lower pressure at the filter gage, then there is a suction restriction causing cavitation. Bubbles with normal pressure means there is an air leak which should be fixed but this is not causing the pump failure. That being said, if the air leak is big enough to cause the pump to lose prime and run dry then the pump will eventually fail due to overheating. No bubbles 3. Voltage at the pump...both undervoltage and overvoltage will cause the motor to run hot. Operable design voltages are normally between 197V and 250V with motor life reduced with extended run time at each extreme. 208V to 240V is normal. 242V 4. What is the motor voltage rating on the motor nameplate...is it 230V only or both 208V/230V...this information will help along with the reported voltage measurement at the pump. The nameplate reads 230/115 5. What are the symptoms of the failed pumps...can you tell if the motor has burned or smells burnt. Both times, I came home and noticed pump was not running. I went over to the pad and the motor was ungodly hot and has even left burn marks on the pipes that are about 5 inches from the motor. I touched it and it was about 3 million degrees. 6. Is the pump circuit breaker tripping...this is a sign there are shorts internal to the motor that are caused by insulation breakdown due to repeated overheating. The pump circuit breaker has never tripped 7. Does the motor stop running for a few minutes and then come on automatically...this is a sign the motor overload is tripping internally due to overheating or high current. Nope, it runs perfectly until it burns out and then never again. My brother in law checked eveything on the electric side and said there is no issue other than the fact that the ground wire was not hooked up. He said since we have had no storms this probably wasn't the issue but he was a little PO'd that they didn't have it hooked up. It is now of coarse.