Your dishwasher on acid… citric acid

In Calgary we have hard water. I had become resigned to the fact that there will be white film on dishes and the dishwasher. But recently I bought some citric acid to use to as a cleaner and to try it as a substitute for vinegar in cleaning. I think the shelf life of dilute citric in water may be a problem, but an advantage of using with citric acid powder is that you can make much more concentrated solutions of acid than vinegar which is 5% acetic acid. There are many links about using citric acid to clean the dishwasher. You can also add it as a detergent booster as enthusiastically endorsed here. It helps to keep hard water from depositing on your dishes or dishwasher, according to the Little House in the Suburbs blog (A simple recipe for making your own detergent can also be found there). I totally relate to the simple joy of seeing clear glasses after years of white film on glasses and a crusty filter in the bottom of the dishwasher. It really does work. Our dishwasher looks like new and the glass and plastic look awesome too.

  • It takes about 2 tablespoons of citric acid to clean the dishwasher. 
  • Use a scant 1 teaspoon for each load with your detergent. 

I bought my citric acid at Soap and More for about $10 for 1 kg of citric acid. So your kilogram of citric acid will last hundreds of loads of dishes. Citric acid is sometimes called sour salt. Upon googling, it can also be found at Asian grocery stores (as sour salt), health food stores, and wine making stores. I saw it at Bulk Barn in a small spice bottle for about $3. Prices can vary quite a bit, I’ve seen prices as low as $5 per kg. Some people use unsweetened, uncoloured kool-aid type drink mix which is mostly citric acid plus flavour.

I just noticed that Canadian Tire sells Lemi-Shine, which is mostly citric acid. I had read about this product on US blogs, but hadn’t seen it in Canada until just recently. (340g for $4.50)

Update: April 30, 2020. I’ve changed how I use citric acid in the dishwasher over the years. Having a look at ingredient lists of rinse agent bottles and MSDS sheets, I started to make up a solution of about 20% citric acid and then add a drop of Dawn dish detergent as a surfactant, which is optional. Given the dilution factor of that one drop over many loads of dishes, I feel comfortable with this, but please do as you see fit. I use this in the rinse agent compartment. I make it up as needed, so about 50 mL at a time.

I notice that my dishwasher doesn’t look like the photo any more. Maybe time for a little extra citric acid .

You can see some lingering hard water deposits on the spray-arm, but the dishwasher has not been shinier.
clear glasses!
… and plastic!

June Written by:


    April 27, 2020

    Where do you put the 1 teaspoon citric acid added per wash? Do you sprinkle it in bottom of dishwasher? What dish detergent do you use with the citric acid and how much? Thank you

    • June
      April 27, 2020

      Hi Betsy,

      Thanks for you question. I have in the past sprinkled citric acid in the bottom of the dishwasher. I used to use powdered dishwasher detergent, either cascade or something in a blue box, the name escapes me at the moment. About a year ago, I started using dishwashing detergent in tablet form, whichever is on sale. And I have started to make a solution of citric acid and a drop of Dawn dish detergent to use as rinse agent instead of using the citric acid in the bottom of the dishwasher. The concentration is very approximate. About 20% citric acid by volume. I’ll note the change above.

    April 30, 2020

    Sounds perfect, thank you! I am assuming you put that homemade rinse agent in the rinse agent compartment. Thanks for your help! Betsy

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