The tanks been up and running since June 30. The only anmonia that I every logged was a couple of weeks ago and it was only 0.5 and only one night. My nitrates and nitrites have been constant at 0. All other parameters are good and stable. My rock came from an established reef tank. This past Saturday I put a couple pieces of flake food in the tank and still no anmonia showed up on my nightly tests. So do you think it would be okay to place a CUC this coming Saturday? If nothing crazy happens between now and then.