So by no means am I a newb this is my 3rd tank going on my 12th year in saltwater. Just slightly perplexed with my parameters. So before I go into that setup is 210 gallon. Proflex 4 sump approx 150lbs of rock and 120 lbs of sand. Bought off of craigslist rock was out of water maybe a month or more no idea on actual ammount of time. Sand is all new. I filled the tank over a course of 3 days with a powerhead keeping a little circulation going on in the tank. Temp is low need to buy new heater its at 64 going to bring it up to 80. SG 1.023 ammonia 0 nitrite 1ppm nitrate 20ppm. I did not add any source of ammonia yet as i just got the water filled completely yesterday. My question being is it possible that the rock still had beneficial bacteria that I am getting readings of nitrite obviously the nitrate could just be from nitrite readings. Obviously going to continue to cycle as i normally would just wanted to hear some thoughts on this. Yes I used only rodi with 0 tds.