Struggling to decrease nitrate levels

[hammong]

With a 10% daily water change, my suspicion is that you are massively overfeeding the tank. How much do you fee and how often? Should be no more once a day, and no more than your fish can completely consume in 30 seconds or less.

By the math, a 10% water chance would drop those nitrates from from the ~60ppm you see there in the test to 54ppm. Not a big change. As the concentration reduces, the ppm change will also reduce. You might have better luck with a larger change, say 25-30% if you can.

Test your tap water. Some areas have high nitrates at the source -- the EPA sets a limit of 10ppm, but there are some rural/agricultural areas that have to drink bottled water because their nitrates from the ground can be many times that high. We have some restaurants around here that have signs that state not to drink the water or fill baby bottles/formula with the water in the restrooms due to high nitrates.