I believe sodium citrate is what you would use, although I do not know the appropriate dosage. You would have to do some research on how much would be needed to neutralize your specific water hardness for the quantity of water in your wash cycle. I have a detergent formulation book somewhere in a box, if you really need the info I can look it up for you. Don't use citric acid, however, since that will neutralize the alkalinity of your wash solution. Citric acid can be used in the rinse, but prior to the final rinse, to neutralize residual detergent alkalinity as well as soften and smooth clothing fibers. My clothes are softer with citric acid in the rinse than without. I'm using Bi-O-Kleen Premium powder. It does contain sodium percarbonate, yet I use it on all my colored items without any issues. For whites I add a tablespoon of Ecover's "Ecological Non Chlorine Laundry Bleach" (pure sodium percarb) and get outstanding whitening every time. Please note that DRUGSTORE.COM carries this product but incorrectly lists its ingredients as those of the Ecover laundry powder. The bleach is pure sodium percarbonate, and you can verify that directly at the ecover.com web site. OxyClean is about 60% percarbonate, the rest is soda ash or other filler. Using drugstore.com pricing (which isn't the lowest), OxyClean comes out to 38 cents per oz. of percarbonate content compared to 29 cents per oz. for the Ecover product. Using a pure product, like Ecover's, has several advantages: You use 1 TBS (1/2 oz.) of pure product versus double the amount of OxyClean. 40% of the latter is yet more chemicals that you're putting into your wash and the environment, with no benefit. It takes far less packaging material, saving on raw materials, manufacturing costs, and the fuel involved in transport. The Ecover product costs 25% less for effective ingredient, so you're saving money too! I know I've posted a few messages here and in other threads about natural products, but I truly think they have gotten to the point of being viable alternatives without compromising performance. Please forgive me if I tend to evangelize, but when I get excited I can't hold it in! :) One note regarding the Bi-O-Kleen powder -- it does not contain any water softening agents. I have a whole house softener, so this is not an issue, but those with harder water (over 8 degrees hardness) may not experience the same results with the Bi-O-Kleen product. With harder water, you may wish to add some citrate to your detergent compartment. An easy way to determine how much citrate to use for your water would be to measure the hardness of a gallon of water (test strips should work). Add a small quantity of sodium citrate, perhaps 1/2 tsp, dissolve and re-measure. Continue doing this until you achieve the softest water. Take this dose and extrapolate it to the quantity of water your machine uses for the main wash cycle. Add that amount of citrate to your detergent drawer, and to the...

I just called the Church & Dwight phone # above and spoke to a very nice lady and ordered 3 boxes of washing soda. She said it had been pulled from most stores because it was such competition for laundry detergents, which made me want to try it all the more. No store in my area carries it any longer. If you call, you may have to wait for several minutes as I did, however, it takes only a few minutes to order after connecting with them. They waive shipping fees of $6.00+ for 2 or more boxes and the cost is now $4.50 per box.

Go to your local pool supply store and ask them for their least expensive sodium cabonate. Washing soda is sodium carbonate, and it is used in pools to adjust pH.

As long as the ingredients are 100% sodium carbonate, you are good to go. Washing soda = soda ash = sodium carbonate. Check the smaller independent grocers in your area, they may have washing soda. Pool supply or grocery store, it's all the same stuff.