Your lighting is fine. It would be difficult to kill plants with light if you stick to lights that are specifically for aquarium use. When using T8s and 12s, you can use the old "watts per gallon rule", so lighting in the 1.5 watt per gallon of tank volume is in the moderate light range.
You have a small tank and that's a challenge to keep clean. You need to do weekly water changes. Remove and replace half the tank water and replace it with pure, treated tap water. Plants and fish do best in pure water conditions.
Your fish will supply the macro nutrients, but you need to add the trace elements (micro nutrients). You can get those at the local pet store, just dose according to container instructions.
Just a couple of ideas for you to consider or not.
I am doing weekly water changes and have seen mass improvement for my fish already, and my plants seems to be perking up