I’ve been doing a fishless cycle with dr Tim’s one and only and dr Tim’s ammonia along with microbactor7. After two weeks I did a 10% water change and my ammonia is now reading .2, but my nitrates are still reading over 50(as high as my Red Sea test reads). Do I need to do another water change or start looking at carbon dosing? My tank has 80lbs of pukani dry rock and 20lbs of live rock from my smaller tank, along with caribsea arag alive sand. Tank is a Cade 1800s2, approx 207 gallons.