I made the powdered detergent but it kept clumping when I loaded it and then wouldn't wash all of my dishes clean. Thought I would try to the liquid and I'm loving it!! My dishwasher is OLD too. Here's the recipe!
Liquid Dishwasher Detergent with Essential Oils
8 cups water
¾ cups Arm & Hammer Super Washing Soda
½ cup Borax
¼ cup Liquid Castile Soap
Essential Oils-4 Drops each: Lemon, Thieves, Purification
Bring 4 cups of water to a boil
Remove from heat and gradually add the washing soda, borax and castile soap.
Stir gently until dissolved.
Once completely dissolved add the remaining 4 cups of water
Place in a container and cover for 24 hours
This batch makes a ½ gallon.
After 24 hours stir the mixture for a smooth consistency. It will look gel like when you first open it.
Fill your dishwasher compartment with the mixture and wash as normal.