I Primed the tank when I first filled it because I knew I didn't want any chlorine or chloramine in there - then I waited for a day because I didn't want the Prime to interfere with the ammonia. I have not added any new water or prime since then, but the level has dropped at least an inch now - I have several gallons of Primed water waiting to top up the tank late tomorrow.
The label, regarding Prime vs Cycling:
"Prime converts ammonia into a safe, non-toxic form that is readily removed by the tank's biofilter. Prime may be used during tank cycling to alleviate ammonia/nitrite toxicity."
It doesn't seem to specify on the bottle what it converts the ammonia to, but they say it's fine for cycling. They also make the case it can be added directly to aquariums when adding water, which suggests it should not impact the bacterial colony - but these labels were all written by marketers. I try to mix these labels heavily with comments online, since experience tells a different story than manufacturers.
The filter currently installed is an Aquaclear-50 HOB - I know, it barely cuts it for this tank, but I'll be adding my TopFin-60 HOB to this tank if it ever cycles. I can't move it over yet because it's keeping my fishies alive in the 25g tank right now. In the meantime, I have lots of water movement and surface agitation in the 45.
For filter media I have the sponge on the bottom, a filter sleeve from the 25g tank (yesterday's seeding attempt), and the bio-media on top of those. I had the carbon pouch sitting between the bio-media and the sponge, but I removed that yesterday to try and get some bacteria moved over to the bio-media.
I'm very open to suggestions, I need to get this tank running. For all I know, all my seeding is being killed off as soon as it hits the water.