So here’s my take on this issue and hopefully a solution for you? As mentioned, regardless of your current nutrient levels, feed your fish multiple times a day (with various food, frozen and pellets, quality matters here). It’s completely safe to dose 1ppm of sodium nitrate (nightly), use food or reagent grade, which can be purchased on Amazon. Use this calculator to find the ratio
Jamie’s planted tank calculator, choose potassium nitrate, as it’s virtually the same as sodium nitrate and will work for this purpose. Slowly reduce your chemical filtration and use
PNS Probio, to naturally reduce your phosphates and “fix” your nitrates as to not deplete them. It’s going to take a little time, but things will turn around. It’s really this simple. Once the bacteria has established itself, it will equal out and then you can utilize
PNS Yello Sno, combined with Probio to feed your whole tank.
Also, slowly bring your alk up to NSW levels 7-8dkh.