Care of small, shady Waterfall

Question:

I have a small waterfall on my front porch. It’s in the shade. I have plants such as ferns sitting close to it but no plants in the water. I haven’t had it very long but it needs something in the water besides what I’ve tried; baking soda, bleach, white vinegar. It’s foamy. even before I added products,cloudy and doesn’t smell good. What do I need to keep it looking and smelling fresh? The instructions just said to take it apart and empty water and scrub bowl. I’m getting ready to go for back surgery and that’s hard for me to do, the lifting I mean. Please give me some advice. It’s a very small fountain, probably 3ft in diameter. Thank you in advance for your help