Ok cool.
Personally I’d start the co2 earlier, maybe 3 hours. Get it a nice lime green before lights come on.
Bigger water changes, as much as you can muster 70%+ no problem. Bigger the better. If you are having problems twice a week for a while. Don’t worry about doing 2 changes on the trot or a running water change.
Turn the lighting down will also assist and then slowly ramp up.
Think about ferts, I donot know the one you are using. Look at the ingredient percentages and compare to TNC Complete, when using tnc complete we usually follow the instructions for EA Aquascaper fertiliser. Rotala butterfly calculator will assist or simply change ferts.
It’ll Probably a lot more than you are doing!
Temporary floating plants are good.
also loads of shrimp (I can’t see any in the pic I looked at) are a must.
Remove any damaged leaves. Blast everything with a turkey baster when syphoning off water and scrub hardscape with a small wire brush. Clean filter often. Anything to remove waste organics.
Hope that gives you an idea.