I would add a CUC, and sit back and watch em work. It's honestly a pain in the ass to do this, because I know you're itchn' to start adding other stuff...but your best bet is to sit back and let nature due the work. I would leave your sand alone, and not vac it...everything you are seeing is basically natural in the cycle, and maturity of a tank. What are you're plans for the tank in the future? Reason I ask is cause it sounds like you're a little light on the amount of rock you have right now. I would double it at least, unless you have something planned that we don't know about
