I was told cc by two different fish stores. I have cc in my 55, and I know several other people who have cc. Personally, if you've already made the investment....do what you think is best as you have past swa experiene, you are not a novice, go with your gut and your experience. I am surprised no one has told you to get rid of the ug filter yet, they did with me. Also, unlike me....set yourself up a good qt tank as well, I need one now but don't have it ready, I just started at this and am not an expert by any means, but I do know that when you research cc vs. sand you will get equal opinions, good and bad, on both, I did. Good luck, our aquarium is my daughters, fun to watch them be so excited, to bad it's so costly.