I starting to have trouble with the plant. The older leaves are starting to turn yellow and develop rusty-looking spots on them. The stem, for some reason, is starting to look as if it is growing roots from the side of the stem. I'm not sure what's exactly wrong with the stem, but it looks very bad. All of the leaf tips are burnt and the top of the main cola is light-burnt. I couldn't raise the lights any higher, so I knew I would have to take a small loss.

[align=center]QUESTIONS[/align]
1. Could someone tell me what is wrong with the bottom of the stem?
2. I tried flushing with plain (pH adjusted) water but it doesn't seem to be getting any healthier. What should I try to do next?
3. Does anyone know what kind of defect the plant has, judging from the look of the leaves with the spots? If so, how do I fix the problem?

[align=center]PICTURES[/align]
1. Picture of the bad-looking stem.
2. Yellow-spotted leaves.
3. I'm guessing its a nutrient burn??
4. Top of the main cola (light burn).
5. Another pic of the sick plant. Help me PLEASE!!!