I have 3 swords in 2 different tanks with basically the same water chemistry.They put out nice growth 'til the leaves are 5"-6", then they get transparent & melt away. I am using fertilizer balls underneath them which are clay with a pinch of micronized iron & about 10 Osmocote pellets. Ph 7.4, GH 150ppm, KH 3-4, DIY CO2. Any ideas would be appreciated. Tom Connors, Pittsburgh Pa.