Which Dishwasher Detergent

Ooooo lets not do supermarkets least not the one you just mentioned although they are excellent for their boxes, anyway, i was reading somewhere this week and i can't remember where but it uses less water in a dishwasher if used once a day full than washing up the same amount of pots by hand although then there is the energy use to think about but then you'd have to use energy to heat the water for the sink.

I would check the ingredients in the supermarkets own green brands, i don't use them.