I have a red flame sword plant that I am currently trying to revive. The substrate I used was fluval and, at first, it started growing really fast! But then it stopped and I am wondering if it started going downhill because one of its leaves started dying? I didn't remove it properly and then it started deteriorating. Since it went downhill, the 2 gal jar I had it in started smelling like sulfur and all of it's leaves started rotting. Right now, Only one leaf is left and portions of it are still rotting. It's roots are also a brownish color. It's currently in an old trash bin that I used for water changes. I'm hoping you guys would have some decent advice for me? It's not dying noticeably anymore but at the point it's at, I'm wondering if there's even any hope left for it. It's not really showing anymore signs of growth but parts of it are still green.