I have this water fountain on top of my mantle and we put clean water in it every time it gets low. Now it is all green and slimey like. We try cleaning the fountain rocks, etc with soap and water but in gets all soapy like afret I'm done. If we put clean water in it why is it getting like this? Plus, is there like a water fountain cleaner some where that will prevent this and such? Or a house hold remady would be nice. Thx.

It sounds like sotihng is growing in there. As clean as you try to make it, stuff will get into it from the air. There are two solutions:
1. change the water more frequently so that nothing has time to grow.
2. make the water inhospitable to life. One way to do that is to mix in some vinegar with the water. It shouldn't take too much. One part vinegar for every 50 parts water should do the trick and still not smell.

So if I put some vinegar then no "green" stuff or bactiera would start growing?

If you put enough vinegar in, it won't. I think that the 1 part vinegar per 50 parts water should be enough. If it isn't, try adding some more.

Also, they sell a fountain additive at Bed Bath and Beyond or Linins and Things that will help control this. Made just for indoor fountains and smells better then vinegar.

Things start to grow in fountains when everything is just right. Warm water, a little air from the flowing water and a touch of sun light. Even though we have not had much in Cleveland.

Thanks for all of the advice!

I'm planning on getting one for
my cats to enjoy, so this thread
is very helpful to me!

FYI, just tested the smell of the vinegar. At 1 part vinegar in 50 parts water, I couldn't smell a thing. I'd give it a shot before buying something (if it doesn't help, you'll only lose a very tiny amount of something that you probably have in your kitchen anyway).

Let us know if it works.