Diapers Reek Of Amonia OR Have Hard Water? *READ THIS*
This is a very common occurance for those with hard water so if your diapers are smelling like amonia then you probably have hard water and are not adding washing soda to your loads. (If you don't have hard water but are getting build up it might be from your detergent choice, which using washing soda will help as well). Washing soda is the best solution I and the other mamas in this group have found to fix this problem, hands down.
If you have hard water you should not be using baking soda at all as this will cause worse build up and remember that while vinegar is great for getting the amonia out of prefolds, it eats at elastic and waterproof materials. When you have hard water most retail detergents, even ones specifically for cloth diapers will cause horrible build up if used alone. (When using vinegar with prefolds you are soaking them in it in a bowl or pot, never put it in the actual washer. This will cause the deposits on the inside of the washer to loosen and they will end up in your clothes and diapers, and actually make the issue worse).
Washing soda is found in the laundry aisle of most grocery stores (not walmart or target) in a yellow box and is called super washing soda by arm and hammer. if you can not find it as super washing soda then look for calgon laundry booster which their only active ingredient is washing soda (but the super washing soda is much cheaper so if you can find that instead, oxiclean can also be substituted as one of it's main ingredients is washing soda).
When using cloth diapers with hard water washing soda is basically necessary to avoid the build up that causes that amonia smell you are experiencing. Use 2 tablespoons added to half the normal amount of detergent you would use in normal cd loads.
Make sure to strip your diapers first to get rid of the build up that is already there. To strip diapers add a good squirt of dawn blue to a hot load of already washed diapers and then rinse multiple times on hot, until you see no more bubbles from soap during agitation (if you have a front loader then do not use this method, only use the washing soda method to strip). Then do another hot load adding a cup of washing soda, rinse another 5 times on hot even if you don't see bubbles, if you are getting soap bubbles with this load rinse until no more soap bubbles during agitation.
You should only have to do stripping once if you then start using half the normal retail detergent amount plus 2 tablespoons of washing soda. If you find you get amonia buildup again and need to strip again do so, and then go down to 1/4th the normal detergent and 4 tablespoons washing soda. I have never heard of any that had to strip ever again after do 1/4th detergent 4 tablespoons washing soda.
note: thought I would also mention since it's along the same subject and can help this issue a little bit, it's a good idea with hard water to clean out the washer once a month or so by dumping a gallon of vinegar into an empty hot water wash. Like mentioned above this will loosen the deposit buildup in the machine and help wash it away so there is less to interfere with your clothes in general.
how washing soda works:
washing soda will actually nolonger exist by the end of the wash because of the chemical reaction between it and calcium sulfate (this is part of what is building up in your cds and trapping the detergent/soap, and the reason that washing soda can help to effectivly strip the diapers and prevents the trapping of soap/detergent to beginn with). When washing soda comes in contact with calcium sulfate (what causes hard water) part of it bonds to it to create a new compound and also sodium sulfate. Sodium sulfate is 100% soluble in water (almost indefintily) and so will completely rinse and wash away and the bonded unit is heavey and so will fall away from the clothes intead of depositing into or onto it (and this is the reason washing soda is effective at keeping build up from occuring) and then wash away with the rinse.
How to find washing soda-
It is not carrier at big box stores like walmart and target usually (you may get lucky though) but most all grocery stores have it in their laundry aisle. The box looks like this- and is called Super Washing Soda by Arm & Hammer.
If you are having trouble finding washing soda call this number: 1-800-524-1328. You may need the UPC code (33200-03020 but can probably just tell them looking for washing soda. They'll ask for your zipcode, then list the stores in the area that recently carried it.