This is my first tank, however, I have done a TON of research and have become quite familiar with the nitrogen cycle and what to expect. I am doing a fishless cycle, and am on day 20. Along the way, I was able to get my hands on seeded filter media which was added to my canister filter. My setup: 75 gallon 2 sunsun canister filters (first 75 gallon rated , second 100 gallon rated) Bio media (mix of few pot scrubbers, 1 tray of seachem matrix, several trays of ceramic rings) Temp set to 85 degree Constant water circulation with a wavemaker I have attached a picture of my results. Questions: 1) I am confused as to where i am in the cycle. I am still getting high nitrites that only come down once i do a large water change. 2) Should I keep dosing ammonia? Lately, I have stopped since that contributes to nitrites going off the charts. 3) What should my plan of action be going forward? Would like to finish cycle so I can add fish.