stall

Hi. I don't post much on here but I'm at a loss. I started cycling my first tank (37 gal, ph 8.2, KH and GH between 15 and 17, temp is around 84-85F) I've added tss+ twice once before I got a new filter (switch as much media as I could to new filter) then added another a little later. Just this...

So I am currently on day 26 of my fishless cycle and like many people, I am stalled for no apparent reason. By day 6 I was already experiencing a drop in Ammonia, my levels where dropping 1ppm over 24 hours and I had Nitrites showing up as well. This lasted for 3 days then suddenly just stopped...