OK, so I ran a negative through my (new to me) Nikor 4x5 daylight tank. It was a negative I had already developed successfully in a slosher tray, so I didn't really need it for anything else.

I practiced loading the somewhat awkward reels for a while, and then decided to have a go with one negative. I ended up with some real problems, and wanted to post the question here what might have happened.
When I develop Tri-X 120 roll film, I use 13 minutes at the 1+1+100 agitation, at 70*F, agitating for the first minute, and then two inversions every three minutes. It works like a charm for me. So I figured I'd do the same with this single sheet of film. The tank holds 1250ml so I filled it to the brim, poured just a little bit out, and started agitating. I used water for stop bath, and in usual manner I used tested (film strip clearing time) fixer for three minutes with constant agitation. The neg ended up with some really clear agitation issues, as well as marks from the stainless steel guides inside the reel.
What am I doing wrong, what kind of agitation regimen do I need with these daylight tanks?

The bright part of the negative is over-developed of course. That's the part that was at the outer 'edge' of the spiral reel. I wonder if that had anything to do with it, or if that was a light leak or something... Anyway, it's pretty ugly...

Thanks,

- Thomas