I am working on that cover around the pond. The small areas that I have improved, have a greatly impoved number a mosquito minnows with small BG at the edge looking for a meal.

I did the jar test (thank you FishinRod). I was shocked how clear (very clear) the pond water was when I put it in the jars which made me re-check the visibilty in the pond, it was >36". Checked again 2 weeks later back to 24"

I used 3 jars, the first in the dark, became very clear. The second in filtered light appeared to have more green in it but not very much. The last I added 1/64 teaspoon of inside granular plant fertilizer & it had about 4 times? the phytoplankton that other jar in light had. Perhaps the brown I see is just a backround color from the pond bottom? I saw no suspended clay or dirt particles. I read :
https://americansportfish.com/fertile-ponds-and-plankton-blooms/

It seems like Voodoo. What is enough & when is it to much? How do you get that green turning to brown-green without overdoing it, yet keep it going throughout the summer? Trial & error? I have never seen that green bean color. I have never reallly observed a great deal of change in the pond color through out the year. When there is a long stretch of very little rain, I have noticed that the visibilty improves but never thought to measure the amount. I would like to know why the visibility improves?