Odd growth on plant
Bear with me here, I'm not very good with plants.
Around December I received an old 10gal from my aunt and uncle that they used to winter their koi in. I cleaned it thoroughly and made sure the cycle was completed before buying plants for the tank.
I believe this plant in particular is an amazon sword, though it's been a while since I bought it and I may have it wrong. It's got some weird sort of brown and green threads coming from the tip of the largest leaf (which is about 5 inches tall). I do 50% water changes every Saturday and use 5ml of Leaf Zone plant food. Every other plant in the tank is doing fine. The tank is divided into two 5gal segments, but the betta belonging to this half (Drift) is in quarantine for a fungal infection. The only inhabitant of the segment right now is a golden mystery snail, and he's not shown any interest in any of the live plants.
Can anyone help me figure out what this stuff is, and how to deal with it?
tailgate (HMDT) ☼ knock out (HMDT) ☼ drift (HMPK) ☼ jazz (HM)
cyclonus ○ breakdown ○ wing ○ pavarotti
(apple snails + bristle pleco)