Do I Need to Use Calgon Water Softener When I Wash Cloth Diapers?

By April Duffy •  Updated: 06/17/24 •  5 min read

Calgon is a laundry product used to soften water. It’s also marketed as an anti-limescale product, which is attractive because hard water can lead to limescale buildup on the heating element inside of washing machines. Modern day Calgon contains the active ingredients polycarbonate and zeolite (the very original version contained sodium hexametaphosphate, a phosphate).

Detergent actually has water softeners in it as well, but if you have very hard water, using Calgon along with regular detergent means you could get away with using less detergent. Calgon comes in both liquid or powder, and has fragrance added.

One of the most delicate laundry situations is of course cloth diapers. Hard water lessens the effectiveness of detergent (it’s so busy softening your water, it doesn’t have the cleaning power), this can lead to both immediate diaper stink as diapers won’t be completely cleaned, and other bigger problems down the road as the minerals in the hard water attach to the fabric leaving them stiff and covered with a residue. Treating hard water with a water softener, like Calgon, can significantly help cloth diaper laundering when very hard water is involved.

What is Hard Water?

About 85 per cent of the United States has hard water, which is water that has high levels of calcium and magnesium minerals. The more calcium and magnesium you have in your water, the harder your water is.

Should Everyone Add Calgon into Their Wash Just to be Safe?

One of the Cloth Diapers for Beginners Facebook group members recently asked, “Do I have to test water first or can I just add Calgon to be safe?”  

My answer is a firm no. If you haven’t tested your water and actually have soft water, in addition to being a waste of money, using a softener in soft water can cause excessive soap suds, poor wash results, and prevent detergent from being dissolved properly. This means a residue of detergent, which can again cause problems.

How to Test for Hard Water

If you’re on a municipal water system, your city’s website or telephone service may be able to provide you with information about your water hardness/softness. If you can’t find it there, or you’re on a well system, testing for hard water is actually pretty quick and easy, you just need to get yourself some water test strips like these ones, which I found on Amazon for a very inexpensive price:

Test strips like these are just easy dip strips that change color according to the hardness of the water. By following the instructions on the package, you’ll get a good idea of what range your water falls into and can adjust your laundry recipe your result.

If you have spots on your dishes or glass shower doors when they dry naturally, there’s a good chance that you have hard water and you should test to be certain.

So If I Have Hard Water I Have to Use Calgon Water Softener?

With all of the above, you might be thinking that if you test your water and it proves to be hard, that you will have to invest in some Calgon, but that’s not always the case. While Calgon is a good softener, it doesn’t do anything vastly different to the softeners in detergent. Testing your water is still the priority. If your water is very hard, meaning higher than 10 gpg or 180 ppm, you’ll need to invest in a water softener, like Calgon, or something else. If your water test shows that your water is hard, but under that, using a good quality detergent (sorry but “natural” detergents or “cloth diaper detergents” aren’t on the top of that list) , in the correct amount for the hardness of your water, and for the high soil level of diapers, could mean you don’t really need to use anything extra.

With that said, if you may also want to consider if the combined cost of Calgon and the lesser amount of detergent could be cheaper than using a greater amount of detergent.

How much more detergent you’ll need if not using a softener will be unique to your hard water and detergent. Start by gradually increasing the amount of detergent you’re using in your diaper laundry until you’re happy with how your diapers feel and smell when they come out of a standard wash. In general, about 30% over the recommended amount of detergent should be enough for hard water that doesn’t absolutely require a water softer.

What Else Should I Know about Calgon Water Softener?

One thing that should be mentioned is that in situations where detergent isn’t used, such as when stripping diapers, Calgon can be used. When used during stripping, Calgon helps to remove hard water minerals and dirt that have built up in the fabric over time.

What if I Have Questions?

Got questions about water softeners or something else cloth diaper related? First, check out the rest of the Cloth Diapers for Beginners FAQs here. If your question isn’t there, or drop into the Cloth Diapers for Beginners Facebook group and ask for a quick answer from our amazing community.

April Duffy

April is the founder of Cloth Diapers for Beginners and author of The Cloth Diaper Wash & Care Handbook. Since 2015, April has helped well over 75,000 parents and caregivers cloth diaper their children through this website, her book, her YouTube Channel, and the Cloth Diapers for Beginners Facebook Group.