So what do you use on the dark areas in front of the couch, heavy traffic area, ect.?
Understanding the souurce and cause of the discouloration comes first. Let's take in front of the sofas or arm chairs as an example.I find that the hardest areas to clean are any ares that is subject to feet twisting and turning on the carpet such as in front of sofas,bottom of landings or areas on traffic lanes where people are taking corners or turns when they are
walking.These areas are subject to much more wear than an area that is just being walked on in a strait
path.When properly cleaned they should not have a blackish color to
them.If their is wear and the carpet is properly cleaned the appearance should be a faded color of the unworn area or depending on the way the mills applied the dyies and the dyies are severly worn of it will in most cases be the color of the carpet before the dyies have been applied which in most cases will be a straw color.
I have come to the conclusion after interveiwing my clients that a lot of the black on traffic areas that is the most difficult to come out is caused from the dyies comming from the slippers or foot wear that are being worn in the home. So if you address this with your pretreatment, life will be good.