Struggling Ludwigia?

[AlexJordan]

I have five stems of ludwigia repens in my 29 gallon, but they  don't seem to be doing well. I have T5 lights that are on for eight hours a day, and dose carbon daily, ferts weekly, and macronutrients a few times weekly. Also, I put iron up supplements in the substrate. The bottom's leaves are falling off, and the stem is darkening. What should I do to help them?

 

[AlexJordan]

Okay, I think lighting was the issue, since the edge lugwigias were doing better. I kicked up the time (somehow it was down to only 5 hours/day) to 8 hours a day. We'll see how they do.