Dwarf sag melting

[DirtyTankMan]

My planted 45 has been set up for a little while now and everything is growing amazingly, I went on vacation and upping coming back my dwarf sag had sprung up to the top of the tank. It was fine for a few weeks and now it is all melting, nothing has changed and all of my parameters are in order. Could it be allelopathy between it an the plants around it or anything else? I recently hooked up a DIY co2 system if that helps..

 

[aqua_chem]

It's almost certainly not allelopathy. Did the sage uproot itself? Is the entire intact plant floating at the top, or just chunks of one? What's your nitrate at?