To do this you can put in a floating de-icer or put a pump in the bottom which shoots a jet of water to the surface to keep it from freezing. For an added precaution you may want to add an aeration system if you don't already have one.
Water Fountain Antifreeze
Antifreeze is a method often touted to help fountains survive the winter, but in fact, you should avoid it when trying to winterize a water feature. While this technically works, it isn't recommended because antifreeze and other additives like it are usually incredibly toxic.
Do not add any de-icing product or chemical antifreeze to a fountain. It will not prevent winter damage, but it will pose a serious health risk to children, pets and wildlife.
Check the Circulation of Water
A pump that provides at least 2,000 gph can be operated throughout the winter without a problem, as long as it runs continuously. Moving water will usually keep a hole open in the ice around the waterfalls and in front of the circulation system.
Keep Water Moving
You will notice that the pond can freeze over quite a bit, but the area around the waterfall stays open. As long as the water is moving, it won't freeze until the temperature gets really low.
Place absorbent materials such as burlap bags or old blankets in the bowls of the fountain. This allows any moisture that gets into the bowls to be absorbed instead of soaking into the bowl material and possibly damaging it when the temperature drops below freezing.
Running a fountain in winter is not recommended when the temperature is below freezing. For fountain freeze protection, Nick's Garden Center recommends that you first unplug the pump and remove it.
Helpful tips to keep your pool and its equipment safe during freezing temperatures. Run your pool pump continuously when temperatures are near or below freezing. You don't need to run your heater, moving water likely will not freeze.
Add Vinegar To Your Fountain
To quickly clean and freshen your indoor water fountain, add a cup or two of filtered white apple cider vinegar. Vinegar exhibits antibacterial, antiviral and antiseptic properties, killing germs on contact. And best of all, it's all-natural and doesn't rely on the use of harsh chemicals.
That means the experience of Epsom salt cold plunging is more aesthetic than medicinal. Adding salt lowers the freezing point of water.
WCCO asked several kids near the falls what it would take to make a waterfall freeze. They correctly answered “cold air” and specifically, temperatures at or below 32 degrees Fahrenheit. Even one night of temperatures 32 degrees or lower can make ice form on a lake, but that's not enough time for a waterfall.
During the cold winter months, the water inside a fountain can freeze and expand as temperatures fluctuate, weakening and cracking the material of your fountain and damaging the pump.
As fish slow down in fall, it is time to shut off any waterfalls, fountains or bubblers and remove the pond's pump to store it for winter. The warmest water will be at the bottom of the pond where fish are hibernating, and continuing to move the water in winter would cool the pond and endanger its fish and plants.
Be sure your pond has areas that are deep enough so it does not freeze to the bottom. Generally 18 inches depth is sufficient, but ponds in extremely cold regions of the country should have areas 30 inches deep or deeper. Use a pond de-icer to keep an area of the pond ice-free to allow toxic gases to escape.
Now is the best time to winterize your landscape water features, before the frost and cold weather really sets in. Winterizing water features in your yard now will prevent complications later this year and will help ensure your babbling brook, waterfall, or koi pond will run for years to come.
Drain the fountain.
Unplug the pump and drain all the water from the fountain. Some fountains have a plug on the bottom for easy draining. If yours doesn't, scoop the water out with a small bucket or use a piece of tubing to siphon it out. If you have a tiered fountain, disassemble it after draining the water.
Mixing hydrogen peroxide with water can create a solution that remains liquid to -57℃. It's an excellent combination for homemade ice packs. However, pouring hydrogen peroxide over ice doesn't result in speedy ice melting. It can melt ice but takes up to three times as long as a sodium chloride salt.