Phosphate free, diaper safe detergent. (For ideas on what types of detergents are safe for your diapers and best for you machine, see ) Washing soda, vinegar, borax, tea tree oil, lavender oil, oxy-clean(or oxygen bleach)
For my old top loader I used X-tra Classic, baking soda or washing soda, or vinegar as needed, and a scoop of Oxi-clean in the hot wash.
With my new front loader, I am using 1/2t of Allen's Naturally, or 2T of Rockin Green Diaper Detergent, a few drops of Tea Tree oil or Lavender oil as needed. Every few washes I will add some washing soda and vinegar or a bit of oxygen bleach to keep the diapers soft, eliminate stains, and make sure there is no detergent build up that would cause odor or repelling issues. The main concern is making sure all velcro or apliz tabs are secure to their laundry tabs and that the woolies are not in the wash...they take special care. I also remove PUL and fleece covers and wash them with my regular laundry. Everything else (dipes, wipes, liners, doublers) goes in the machine.
Run a COLD wash with no detergent. You can add some vinegar and washing soda to this cycle if you desire. It will help to balance the ph of your diapers and make your detergent work better.
Loosen dipes from side of washer, and run a full HOT wash with detergent and essential oils and oxiclean or oxygen bleach if desired.
Loosen dipes again and run an aditional HOT wash, followed by an extra rinse if there were any bubbles remaining in the rinse of the previous cycle. If there were not, I still suggest at least the extra rinse.
Dry in the dryer or on the line. It may or may not take 2 dryer cycles to get them completely dry
Those with hard water issues may end up with mineral buildup (and a case of the ammonia stinkies). I suggest using a capful of Calgon Liquid Water Softener or 1/4c of Calgon Powdered Water Softener every other week or so. If you have REALLY hard water, you may want to up that to weekly.