Though you didn't give us all of the answers to the numbers for ammonia, nitrite, pH, and temperature, you have given more than most. The air temperatures don't really tell us much about what the water temperature is, and it is the water that the fish are living in, so it is the important one.
The green (algae growth) is usually a sign of sap fungus which has trapped algae within its spores. The flashing is most likely parasites and if you have a microscope, it is always a good practice to scrape the fish to see who is irritating the fish and that also gives the best possible treatment, but without a scope, then the next best thing is a shotgun treatment to kill everything. For this shotgun, start with Proform C or similar formalin/malachite green formulation which will kill most of the microscopic parasites and fungus. This is a 3 day treatment with a treatment every day with a 25% water change each day before the treatment, and follow with a fluke treatment, like Fluke M or Prazi allowing this treatment to remain for a minimum of a week with no water changes. If water temperatures are below 50F, the formalin /malachite green treatment cannot be used, so you may need to wait a few days before starting. I would also get and have on hand Tricide Neo antibiotic treatment so that if there are wounds/ulcers treatment can be started early. It is not uncommon at this time of the year that the bellies of fish which have been staying pretty much stationary in contact with the pond bottom will show sores which need to be treated.
Zone 7 A/B
Keep your words sweet. You never know when you may have to eat them.
Richard