All of us who live in Germany are familiar with it: laundry detergent that just contains the basics, to which water softner and stain remover must be added as needed. The idea is to release as few chemicals into the environment as possible when doing laundry.
Not surprisingly, this is a completely foreign concept in the US and I have not found reference to it in other English-speaking countries in my Internet searches. At the moment, I have a literaral translation: building block detergents, but it does not really please me.
hi, unfortunately not the ready-made translation, but some brainstorming ingredients: no-frills less colloquial would be plain, as in plain detergent. Baukasten as in Physik- oder Chemiebaukasten is "set" in English, you know, the experiment boxes 12-year-olds get (or used to). But as you indicated with your building-block translation, they probably don't want you to experiment with the detergent, but to make your own, in which case, I'd rather use components than building blocks (latter being too literal). Another word you might consider: "modular"? Then there's tailor-made and customize, but you have probably thought of that yourself. Anyway, I think what with this whole "DYI-detergent-to save the whales"-concept being so alien to anyone not German, even if there was an okay-sounding translation, you would probably still have to explain a little.
tanja: Modular is the best solution I have come up with so far too, though I added a comment to indicate that this was a term I had invented, not one used in the US or UK as far as I can tell. None of the major English-speaking detergent manufactures have anything like it, at least as far as their on-line information would indicate.
Vielleicht kannst Du etwas mit "add-on" anfangen, schliesslich ist das Basiswaschmittel gegeben und wird entsprechend den (vermeintlichen) Beduerfnissen erweitert. "modular" finde ich sonst auch den besten Vorschlag.