Thanks for the aeration advice Bill.

We made the pond a stretched out "S" shape, narrow and long on an East-West axis to minimize the effect of our frequent 30+ mph wind. I didn't think about D.O. I hope to establish submerged vegetation down to 8 feet or so. About one third of the pond is 10 feet deep. I thought if the pond has 8 feet of oxygenated water, it can support fish. The extra depth can collect sediment for the next 20 years.

Other than lime, I don't plan to fertilize the pond or feed the fish. I am not trying to maximize productivity. The goal is reasonable numbers and size of fish in clear water. Fish management through selective harvest until that doesn't work anymore.

Testing to determine how much clearing agent is needed first and periodically afterwards.

What else do I need to know about the pond? If D.O. is an ongoing concern, what is the most cost effective way to check it down to 10 feet?

When dinosaurs roamed the earth, we used a Secchi disk for clarity measurement ( I bought one), a Kemmerer bottle to sample water at various depths for lab analyses and Hach kits to use in the field.

I thought about getting a binocular microscope to look at plankton and benthos. It would be fun for a while, but does that have any practical value for pond management?

Am I am overthinking this? Maybe just throw in ag lime until it clears. That should raise pH, create a pH buffer and increase available phosphate until the lime is chewed up. If that fails after 2 or 3 tons added, go to alum/hydrated lime or gypsum. There are simple tests using gallon jars to determine the amount of treatment.