Yeah the background looks much better. The cloudiness is normal due to the new substrate. I'm not sure about the flourite but I've used floramax. Did you rinse the substrate and use the included biomagnet solution? Well that Seachem Clarity should help if it's a water clarifier. It will also help to do partial water changes and to add some filter floss to the filter to catch the finer particulates causing the cloudiness.
I don't know much about that fixture you purchased, so i can't comment. I just hope it's intense enough for the HC. When i think HC in a tank that your height, i think T5HO. But I'm uncertain. And if you ever want to give pressurized co2 a whirl LMK. I can help piece a decent setup for about $150-$170.