Diatoms will reduced over time with good husbandry. They are just part of every new tank and even established tanks can get it from time to time.
Just keep up on your water changes. Looking at the photo, the tank doesn't look bad at all. You should of seen the outbreak I had in my tank. Make you rethink the hobby, LOL.
Just keep at it and give it time. If you add a bunch of CUC its going to help but once your out of the woods for algae there will not be a lot for them to graze on in a 10g.
If you feel its too crazy for your liking, run no lights for a day or 2 and see if that helps.
I wouldn't consider a tank mature till at least 12 months. Even then, you are battling certain things.