homemade laundry detergent that actually works in hard water areas?

[trinity_gal]

I've tried only couple of recipes for homemade laundry detergents but both were useless DISASTERS (nappies still came out stained and dirty)- I know I should just adjust proportions and amounts but our washing machine is rubbish (rented apartment) - it takes 2.5hrs to complete washing cycle at 40C, so I have loads of other laundries to do so not much patience for experimenting....

Sorry to be impudent but I wonder if you have a good recipe to share that actually works hard water areas? And how much is needed per wash?

I have so far...
- borax
- baking soda
- washing soda
- white vinegar
- scented soap bars
- Dr Bonner's castile liquid soap
- essential oils

Would be so grateful for ideas and suggestions! Thanks in advance.

PS. if that makes the difference, I have front-loading machine - top-loading is unheard of here...