Stains were mentioned.
Stains come from chemical residue. This suggests you're using plastic reels and/or not doing sufficiently careful reel cleaning between processing runs.
Plastic reels are hard to clean totally, but if you wash VERY thoroughly, with intense flow of water, between processing runs you will reduce contamination of film by residue.
If you're using somebody else's old plastic reels, that may be part of your problem. Used plastic reels may be impossible to clean adequately, once somebody's used them, let them sit around after failing to clean them carefully enough.
I'd suggest steel reels but a lot of amateurs believe mistakenly that plastic reels are easier to load, due to false advertising that Patterson and others place in low level magazines. Pros virtually always use steel reels, specifically because plastic is actually HARDER to load and difficult to clean. Patterson/Jobo uses plastic only because Patterson/Jobo is a plastics company, not because it's a proper material for the job.