Here is my advice but it is free and you are going to get exactly what you pay for...Nothing.

Nothing is what I do to my pond. Ok, not exactly "nothing". The only thing I do, is measure dissolved oxygen, pH, ammonia, nitrites, phosphates etc. and chart it all on a Excel spreadsheet. I test monthly at minimum in four areas, inlet, outlet and two arbitrary areas in between. I look for trends and or anomalies.

After two years, I mated my water quality with the aquatic life. I let the pond dictate what I put in it, instead of dictating to the pond what I wanted in it.

To this day, I still do nothing...No feeding, no aeration, nothing besides continuously checking the water quality parameters.

I live with nature, I don't work for it.