Rotala is a quirky plant. I've had it in my 29G with 35W T5 HO strips. From my experience, if you get the plant when it's already about half tank, it will do well. However, if it's in the lower part of the water column, the light is diluted enough where it can do poorly even if supplemented with nutrients.
When I removed my Rotala, trimmed it down, and dropped it in my 10G with only 20W of 6700K light coming out of a desk lamp stand, it went nuts with no CO2. It grew lush and changed pigment to pink/red towards the top.
In conclusion, from my experience, Rotala loves the light. The more you have of it the better the plant will do. In a shorter tank; however, you will need to trim the plant at the roots every couple weeks.
Here is the Rotala when I first planted it in my 10G from the 29G after disappointing growth:

After less than a month:

You can see how red the plant has turned it had reached the water's surface a few days prior.