So I have a 20 gallon long tank that I decided to cycle with tetra safe start, I’ve heard great things and I usually cycle my tanks by fish less cycle. I currently have two mollies, the Dalmatian is aggressive and chases the other one and she shows signs of stress once in awhile and sometimes curls her tail a little ( I will most likely return her to petco tomorrow) the other mollie which is a ballon mollie doesn’t show signs of clamp fins but doesn’t swim as much. They both gulp at the surface sometimes and eat moss off the wood decor. Ammonia was at a light green but I’ve been using prime (so that could affect that) nitrites was at 0, and nitrates was at 5. I just completed a water change just in case and moved the filter higher to create more surface movement. Am I doing something wrong or just bought a bad stock from petco?