Sun grows ALGAE!!! That is a fact! Your pond needs to be covered 70% to control algae naturally. Another option is to use an Ultra Violet light. The light will kill the green, and keep your pond crystal clear. We can get any size in these. Keep in mind we recommend that you change bulb every 12-18 months.
Salt!!! Salt improves gill function and reduces stress in fish. Salt also helps reduce the toxic effects of nitrites. Please consider the use of pond salt. However remember plants have different levels that they can handle. 1 cup to 100 Gallons.
Keep the dying leaves and dead blooms pulled off of plants. Leaves can turn your water a dingy brown color.
Chlorine....When you have city or county water you have to dechlorinate it when you add water. If not the chlorinated water kills all the good bacteria and can kill your fish.
Never put any other water from any other place in your pond this transfers bacteria. Float fish then only add fish not water, rinse off roots of any plants.