Here’s a couple recent pictures:
I see stem elongation on the older part of the rotala, which can often point to gas issues, either poor gas exchange, or CO2 that isn't at a good level. This is irrelevant if that growth did not occur in your tank however. It may only point to the condition the plant was grown in prior to your purchase.
The rotala in particular is stunted though, which can happen for many reasons. I would know, I've got some in my tank that stunts every time I change a parameter enough. So far I've seen large KH shifts, large CO2 shifts, and running out of Magnesium cause it. I still think Roy may be right with a Magnesium deficiency, but it looks like you've got a few things to consider:
pointed out, you'll need to watch NEW growth to see if your changes are helping.
Your clado algae in the back and along the substrate may indicate poor flow, especially in the back near the buce, I don't know about that one, but many buce enjoy good flow.
Your AMOUNT of light as mentioned above looks to be around medium, but how long are you running lights? I'd cut your photo period to less than 9 hours with that clado showing up, my personal preference would be 6 or 7 hours until things have settled more, a few months from now.
It's a bit less likely, but also entirely possible that you could have too much of certain nutrients as well. I'm less familiar with those signs though so I can't weigh in on that possibility.
Regardless of nutrients, as mentioned before, you want to see a full 1 point (minimum) ph drop by lights-on and maintain that level throughout the photoperiod.
I don't know what method your using for CO2 injection, I may have missed it, but my DIY Rex Griggs style reactor takes many hours to reach the point I need. I'm working on fixing this, but just be aware you may need to start gas as much as 4-6 hours before lights on depending on how you inject and how much. Getting CO2 dialed in just right can take a few months, so be patient with it, but once it's doing what you need you shouldn't need to adjust it much anymore.