melt

Hi there, I just noticed that all of the anacharis in my tank is undergoing a random-seeming melt. For context, the anacharis has been in my tank for about 6 months, and we grew it from a single dying stem that came with some shrimp we bought. Anyway, now almost all the anacharis is melting...

I like the look of vallis as a background plant for my tank but throughout the years it continues to just melt on me. I've tried both spiral and straight types with and without EasyCarbo/ferts yet it died regardless. If anyone can shed light on the cause of my issue that'd be great. Is there a...