Hand washing vs the dishwasher.

A little checking around tells me that using the machine is better, environmentally and otherwise, than hand washing. I believe that, especially for a single like me. I use the machine once a week (no pre-rinsing, I put the dishes in the machine as I use them), but when I used to hand wash I washed most every day.
I don’t use “heated dry”. I just leave the door open.
I’m looking for an environmentally more friendly detergent that works. Any suggestions?