While you are not required by law to change your garden fountain water, you will really suffer the consequences when the basin becomes dirty. Most fountain specialists recommend that you change your pond or fountain water every 4-6 months. This does not refer to the process of adding water, which should be done on a more regular basis. This refers to emptying out the fountain, cleaning the fountain pieces, and then replacing the water. You are also advised to clean the pump and get rid of all the debris that has floated into the rotors.
How should you go about replacing garden fountain water? It mostly depends on the type of fountain you have as well as the size of it. If you have a smaller basin then you could just poor the water down the toilet. (Try not to use the sink as the water could be filled with algae and leave behind a bad odor) Some fountains actually have a drain plug feature which makes it easy to activate the drain and let all the water flow into the ground.
If you have a smaller fountain then by all means disassemble the garden water fountain completely so you can thoroughly clean it. You could also use an extra pump to remove the water from the basin or use the existing pump that re-circulates the water. Remember, as long as the pump is below the surface, you are not damaging the garden water fountain. All you have to do is attach a long tube to the pump and then lower it into the basin. After you have cleaned the basin you can add water back to the fountain using a garden hose or pumping in distilled water.
There is another method of replacing water with garden water fountains and this is called siphoning. In this manner, you get rid of garden fountain water the same way you would replace the water in a fish tank. You get a plastic tube (appropriate to the size of the basin) and then put it inside the fountain. You take the other end and suck the water out as if you had a giant straw. Of course, once the water reaches your mouth you want to let go and let the water flow into a bucket or a container. Remember, if the basin or container is lower than the fountain gravity is on your side. Just make sure that the tube is clean and please do not drink the water! There are more bacteria and chemicals in there than you care to know!
Garden water fountains are easy to assemble and disassemble. Replacing the water is just easy. Before long, you can have a completely clean and fresh waterfall or fountain running!