Providing a picture would be very helpful in diagnosing the problem. Sometimes, the longer banana plant leaves can turn red as they get closer to the surface. This is a form of protection from brighter light. In contrast, if the lights are too high from the substrate, your plant(s) aren't getting enough light to properly photosynthesize. If you say that they're dying back, there's clearly an imbalance somewhere. How is your dosing regimen for ferts (micros/macros)? Seeing a picture of the tank, and knowing what your maintenance schedule looks like would be helpful.