Ingredients:
2 cup All Natural Borax
2 cup washing soda (if you don't have this I know some people use baking soda)
1/2 cup Citric Acid.. I have lots of this from canning season (fyi: don't buy this in the little shaker thing on the canning isle of the grocery store or you will kick yourself in the butt with the price... I go down to our local DIY Beer Brewery supply store and get a nice size bag of it for $5 and you get a lot more) any whoo where was I ... if you don't have any two packets of kool-aid works too (I don't ever have this in my house)
1/4 cup salt... I used canning salt some say use kosher salt... I improvised :)
1 tbs lemon zest I like it for the smell thats all
white Vinegar

Crunch numbers and it comes out to be about.... wait for it..... $0.06 per load :) much better than what your buying at the store right?!
Oh and don't forget if your leaving this out on the counter or window put it in something pretty to look at or a old large yogurt container works well for under the sink.