Hello again...
Have you tried not jumping through so many hoops for your tank and just do the basics. If you keep your tank duties simple, your fish and plants will take care of themselves and the hobby will be more enjoyable. Feeding: Fish can easily subsist on 2 feedings a week, just feed a variety. Frozen, freeze dried and flakes. The vast majority of aquarium fish will adapt to the vast majority of public water supplies. Your nitrates are high, okay. This form of nitrogen is at the tail end of the nitrogen cycle, so it isn't toxic to your fish. Even high levels will at most cause a very slight discomfort. They'll adapt, tank fish have for decades. Floating plants use nitrates. Pennywort, Anacharis and Hornwort are very good and grow in most light conditions. Algae grows naturally in a healthy tank and is good for your fishes' diet. Change out the water frequently and you maintain a stable water chemistry and safety for the tank inhabitants. A stable chemistry is more important than a particular chemistry. There's not a fish out there that won't benefit from large, frequent water changes.
Good luck sifting through all the information you're getting. You don't seem to be having any fun in the water keeping hobby. Maybe if you simplify things a little, there won't be so much to remember and the hobby might be more fun.
B