I am new to the planted tank hobby. I have kept saltwater reefs but not planted tanks so I need help. I have a 20 gallon high with a betta, shrimp, and plants. My plants are not growing well and turning brown. I dose seachem nitrogen, iron , potassium, and flourish. I run led lights I have taken from my saltwater tank and a internal power filter with carbon. IDK if this has to do with anything but when I first set it up my mom accendently cleaned my gravel I was going to use and was stocked with bacteria so I had to do a mini cycle and my most of my shrimp diedenver and my betta got finished rot. It is cycled now but my planted are not doing well. What am I missing? Is it because of the carbon? Am I missing a macronutrients?