Okay, so I could definitely see it being either of those things. When removing the wet negatives from the PrintFile, they stuck a bit and I had to pull hard to get it to budge. When I initially rinsed after development for 7 1/2 minutes, I used about 20C as recommended. Today during re-rinses, I didn't use a thermometre and the water was warm, warmer than usual. From playing with the water temp before developing to get things right, I'd guess it was over 35C, though I can't be sure. Any idea to tell exactly which it was?

I guess I'll know for next time to be 100% sure that the negatives are dry and if I need to re-rinse, that I check the temperature. Is there anything else it could be?

Yeah the hard water is an issue in Alberta. The water marks are really irking me. The distilled re-rinse helped 90% of it, but some still remains. I'm guessing next time if I combine final rinse with Ilfotol it should get rid of 99%. Ironically, I haven't had dust issues. My lab processed negatives are often dusty, but mine aren't. It helps I think that I chose the least dusty room in the place and ensure there is minimal movement in the room when the film is drying.

Thanks for the help so far guys. This has reassured me, I was a bit paranoid about shooting more b&w. It is weird though - on re-rinses on previous rolls, I didn't check temp either and no scaley reticulations occurred.

It may also be worth noting that the first 9 frames are without this issue. After that, it starts getting ugly. Those first 9 frames I think I only re-washed once and then let them dry and put them in sleeves. They still have some water marks that only show up in some scans. But I only ended up re-washing the other strips.