Bought that novus 3 part polish kit from bulk reef supply. I was skeptical but it worked incredibly well. It takes a little time and effort but it works wonders. I had some pretty deep scratches and I'm talking like 6-10 inches long. You wouldn't even be able to tell me where they were. I did it over a couple days for like an hour at a time because my arms got tired lol my tank is also 8' long with like a 6 inch euro brace around the top. So I had to reach in past that to hit the inside. It sucked but it was 100% worth the 28$ or whatever it cost. My tank was empty too