Compaction is bad...I had it in my 90g, i had all sugar fine in it. Some people will mix sugar fine 0.2-1.2 mm with a larger size say in the 1-4mm grain size range. Haven't done it myself but some say it works.
I've had a 55g tank with CC for about a year now and I've had high nitrate problems nearly the entire time. I bought the entire tank setup from someone so the CC had already been in use for some time. I've been considering changing it out for a live sand bed, but I'm unsure how to go about this without completely disrupting my entire system. Does anyone have advice on how to switch from CC to sand?