Ive had this sword for about a month and a half. It started to melt back, which was expected. The new growth leaves were sprouting out and growing extremely well, until about 2 weeks ago (1 month in tank). I suspected it had already eaten all of the root tabs (2) I placed underneath it. So, I added to more directly under it.
Now the plants leaves are looking black, but it doesn't look like the black beard algea I have seen. I also watched all of the nutrient deficiency videos, and this doesn't seem like any of it unless I'm missing something. l
I use API root tabs, dose 3 ml of seachem flourish every 3 days, and api c02 booster 4 ml every day. Water is 76-77 degrees, GH ~75 ppm, PH 7.0, near 0 Nitrates/nitrites. 36 gallon tank.
I have a 27 w led about 9 inches above the tank, assuming each light is 1 watt?? 18 inch deep tank.