First thing that u should do is to calibrate your systems. and see that ur negs are not "underexposed" or "underdeveloped" regarding fogging, u can test it out as bellow:(posted 9094 days ago)Take a piece of paper, cover it half way and expose it under enlarger light let the piece be there for some time or try taking it near to all the things that u suspect are fogging it. eg. wall tiles, timer scales LCD panels etc then, develope that piece if the covered side is pure white then be sure that u have messed up with the Shooting exposure, or the Developing all B/W people out there please correct me if I am wrong thanx