Choosing a good detergent (II)

As for colored stains, the same case applies. To save on cost, you can use persalts (perborates) which release oxygen and operate at high temperatures, generally from 80 °. If you are washing with cold water or water of low temperature, these salts normally do not take effect, leaving the stain on the clothes. Modern chemistry had developed salts (pyrethrins) that release oxygen at low temperatures, generally from 30 °. These act easily in the oxidation process (bleaching), but of course these salts are considerably more expensive than those operating at high temperatures, and are only found in high-end detergents, which of course are not as economic as the so-called "cheap" ones (although I think that the latter comes out more expensive in the end)

The same happens with dispersants. They are very important as they prevent dirt that is present in the laundry tub/ soak to  redeposit back into the fabric (technically this is what we call "graying", which is one of the problems  referred to by Beatriz, (read in one of the questions in this blog). To make the product cheaper, some manufacturers reduce the amount of dispersant needed in the detergent. With these types of detergent, what happens is that you end up dying your clothes gray with the dirt present in the wash solution . Dispersants in good quality detergent is what makes the other components effective, leaving the fabric clean and white, free from "graying".

As for calcium sequestrants, the same case applies. If they are not present in sufficient concentrations, the calcium present in the water does not allow the soap and  the other components to take effect. Hence, the detregent ends up being useless for laundry.

And lastly, to comment on the issue of scents. It is the component of the lowest cost and is present in large amount in cheap detergents. This is the only compound that is actually dispensable in the detergent formulation. A good detergent must not leave any odor. The only smell that should stay in the fabric is the "clean clothes" smell, the odor proper of cotton and nothing else. The generous use of this resource by detergent manufacturers, is due to the fact that psychologically,  the clothes that were washed and were left with a good odor gives the consumer a  clean feeling (wrong feeling), eventhough the clothes were actually badly washed. ("Ummm it smells good, it smells like rose or lemon, but my clothes are gray"). If we want our clothes to have a certain pleasant smell, we can choose the specific scent that we want and apply it through the fabric softener, closet fresheners in sachets, aromatic bars for the dryer, etc..). With that we do not settle for the scent (which are sometimes very unpleasant) that manufacturers put in cheap detergent.

My advice is simple, do not fill both the washing machine,  use a washing setting/ program that runs at a slightly higher temperature, between 40 ° and 60 °, and above all use a good detergent.  All detergent manufacturers have their high-end product, the best of each brand, which although would cost a little more at the time of checkout in the supermarket. But it is actually at this moment that you start to save (and to have your clothes properly cleaned), which is what washing is all about, right? And finally, forget about those cheap, attractive detergents which we have mentioned above. Just imagine what they truly are selling to you in those colorful camouflaged packages.