I recently purchased a used 120 gal. I just got it up and running and now I am patiently waiting for things to start brewing. I have 80 lbs of live sand, 50#s dry rock and 10#s live rock. I have been running it for 3 full days now and plan on waiting a couple weeks till I move forward. I altered the wet dry sump to fit 2ea 8" socks. Originally came with bio balls but I decided the sock method was better for me. There is a hang on overflow box with 2 bulkheads, they continue to make a loud gurgling noise, i have been adjusting the flow with a couple shut off valves connected to an external pump which has helped but I still feel it could be quieter. So far everything looks good, I am wondering how long it will take to see the dry rock change into live rock. Should I do water changes at this point? I do have a test kit which I did last night, all 4 test results were where they should be. I guess just wait at this point......patience is my biggest enemy!!