Homemade Dishwasher Detergent (powder)
2 cups Borax
2 cups Washing Soda
Combine well and store in a 32 oz. container. (I used two 16 oz. sour cream containers.)
Use 2 Tbsp. detergent per wash.
Yield: 4 cups/64 Tbsp./32 loads
For a scoop to keep with the detergent, I used an old Country Time lemonade powder scoop (from their extra large container.) One scoop holds a little over 2 Tbsp. You could use any leftover scoop as long as it fits just 2 Tbsp.
And what about a rinse aid? That blue stuff is really expensive! A super cheap alternative: white vinegar. Toss 1 - 1 1/2 cups vinegar in during the rinse cycle of your dishwasher, or pour some into your rinse aid dispenser. (Another tip from that wonderful book Homemade.)
On another note, finding Washing Soda out here in Maryland has been a nightmare! No grocery stores carry it. But after a search online, I found that some hardware stores do carry it, including Ace Hardware. In fact, if your local Ace doesn't have it on the shelf, you can buy it through their website and they'll ship it to your local Ace for free. Nice! I made the 20 minute drive to the closest Ace store and bought all the washing soda they had on the shelf. I am now officially stocked up. :-) (Okay, so they only had 3 boxes, but the trip was so worth it! I forgot how fun hardware shops are to look around in!)
You might be wondering if there is difference between Washing Soda and Baking Soda. The answer is YES! "The chemical name of washing soda is sodium carbonate, it is also known as soda ash or simply soda crystals..." It is also slightly acidic and will therefore wear down fabric and elastic bands faster than baking soda.
"Baking soda is a bicarbonate of sodium or simply stated it is sodium hydrogen carbonate." (or sodium bicarbonate) We use baking soda, obviously for baking, and it is slightly alkaline, so it's somewhat gentler than washing soda.