I have java ferns that used to grow and propagate rapidly to the point where I started throwing them away, but for the past few months they are gradually turning brown on some leaves and dying. Also, my sword which has flowered is growing new plants, but they look weird like pieces of the leaves are missing. I use Excel and have been dosing Plantex and potassium at water changes. Any idea what deficiency this may be indicating? My anubias and crypts are doing well.