Water Features

I fish out the green floaty stuff with a stick. But the water itself is clear, it's a question of not letting debris accumulate and getting enough shade. I have a miniature lily and a native plant with similar leaves. This cuts down the light and suppresses growth in my pot pond

Barley straw. You can buy it in little bales, or in liquid or Pod form.
We got the pods for our container pond.
We also bought a little solar fountain to keep the water moving.

Copper pennies kill algae, I use a few in my water feature. They have to be older ones though, as modern ones aren’t pure copper.

6% food grade Hydrogen peroxide a capful or three in the water, depends on how much water. Safe for the birds, ours swim in and drink from it.

www.ukwaterfeatures.com/products/fountain-fresh.html