Giant Ambulia melting?

I've got some giant ambulia that was nice lush and green when i first planted it and now it's starting to look a bit malnourished and ugly. Light is on from 9am - 10pm, substrate is sand with root tabs. Dose a little bit of iron once a week after a water change but that's it. What could causing it to wither when all the other plants seem to be doing great?

Try reducing your light back to 10 hours per day

itiwhetu said:

Try reducing your light back to 10 hours per day

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Ok got it set to 11am-9pm. I'll see how that goes! Might cut it back a bit to allow new stems to grow too.