Based on this information. it is not a good idea to do all the laundry on Gentle cycle:
“Keep in mind that the three factors involved in getting laundry clean are: agitation in the wash cycle, detergent, and water temperature. How clean your clothes are depends on each of these three aspects.
The normal cycle often lasts anywhere from 8 to 15 minutes. This is the actual time the machine spends agitating the clothes to get them clean. This cycle uses a ‘fast/fast’ combination, meaning the washing cycle is fast and the spin cycle is fast as well. Cottons and linens are fabrics that tolerate the normal cycle very well. They are sturdy fabrics that can withstand this degree of agitation and clothes come very clean as a result. Jeans, towels and bedding are also fabrics that tolerate this cycle well.
Items that are heavily soiled must be washed on the regular cycle. Whether the problem is a heavy amount of sweat, heavy staining or heavy dirt the item will not come clean without a significant amount of agitation.
The Permanent Press cycle lasts on average from 7–10 minutes and uses a ‘fast/slow’ combination. Again, it uses the vigorous speed of the actual washing cycle and uses a slow spin cycle. While the slow spin cycle does not extract as much water from the clothes, it does prevent a good amount of wrinkling.
Synthetic fibers are known for harboring smells and they can only be removed by the agitation experienced in a fast cycle. Synthetic fabrics are also known for pilling, and it is only increased with friction. By choosing a slower spin cycle, it also helps decrease the wear and tear on the fabric, thus causing less pilling. It is primarily used for synthetic fibers such as rayons, knits, polyesters and acetates.
The delicate cycle is designed to be less abrasive, using less agitation. So while it provides less wear and tear on your clothes, it also decreases the level of clean in some instances.”
Mama’s Laundry Talk