Right now I have a 14g cube (15" square) and the substrate is white sand. I have a few different plants, temple, ludwigia repens, ludwigia super mini reds, rotala indica, hornwort, and pennywort. I have this light https://www.amazon.com/gp/product/B08SBPVXCW/?tag=ff0d01-20 and for nutrients, I...