The impact of water hardness on washing cloth diapers
Coralie Mabouledecouche
The quality of your cloth diaper wash depends directly on water hardness and the correct detergent dosage. Understanding these two factors helps prevent buildup, optimizes cleaning, and extends the life of your diapers. Here's how to adapt your routine based on your water composition.
Summary
The importance of water hardness for washing cloth diapers
Hard water can reduce the effectiveness of laundry detergent, leave residues, and damage fabrics. Conversely, very soft water produces more suds and can lead to overdosing. Knowing the composition of your water is therefore essential to preserving the absorbency and durability of your reusable diapers.
👉 Also read: Maintaining your washing machine for optimal washing .
How to determine the hardness of your water
Water hardness varies by region. Here are three simple ways to determine it:
- Check your water supplier's website or municipal reports;
- Use a test strip available in store or online;
- Check on the official map of water hardness in France .
👉 If your water is very hard, find out: how to soften your rough washable nappies .
How to properly measure laundry detergent for washing cloth diapers
Using the correct dosage ensures effective washing without residue or buildup. Here are the guidelines to follow depending on your water hardness:
Soft water (0–15 °TH)
- 1/3 dose for pre-wash;
- 3/4 dose for the main wash.
Medium-hard water (15–30 °TH)
- 1/2 dose for pre-wash;
- 1 full dose for the main wash.
Hard water (30 °TH and above)
- 2/3 of the dose for pre-washing;
- 1 full dose “heavily soiled laundry” for the main wash;
- Add sodium percarbonate to enhance the cleaning action.
Tips for adjusting the dosage and avoiding residues
How to recognize an incorrect dosage
- Persistent odours → lack of laundry detergent or temperature too low;
- White marks or stiffness → excess detergent, insufficient rinsing;
- Reduced absorption → machine too full or poor mixing.
👉 Also check out: how to properly fill your washing machine .
Mistakes to absolutely avoid
- Never under-dose laundry detergent: this promotes bacterial growth;
- Do not use fabric softener: it clogs the absorbent fibers;
- Do not wash below 40°C: heat is essential for disinfection.
FAQ – Water, laundry detergent and washable diapers
Why does water hardness affect washing?
The limescale present in hard water partially neutralizes cleaning agents, thus reducing the effectiveness of laundry detergent. Adjusting the dosage compensates for this effect.
How can I tell if my water is hard?
A white film on your glasses or the heating element of your kettle indicates hard water. You can also use hardness test strips.
What should I do if my diapers come out rough?
Add an extra rinse or a little citric acid to the fabric softener compartment to dissolve limescale naturally.
Can I use an eco-friendly laundry detergent with hard water?
Yes, but it must be dosed sufficiently and combined with a natural anti-limescale agent (such as percarbonate or anti-limescale balls).
How to avoid laundry detergent residue?
Slightly reduce the amount of detergent and opt for a long cycle with a thorough rinse.
Conclusion
Adjusting your detergent dosage to your water hardness is key to effective washing. This helps preserve the softness, absorbency, and longevity of your reusable diapers. A well-calibrated routine means more effective diapers, healthier laundry, and optimized maintenance over the long term.
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