Hard water and a dishwasher

October 18, 2023 10:52 AM

It turns out that I've moved to a city with very hard water. Pans and metal measuring cups are coming out of the dishwasher with a lot of white stuff on them. Googling seems to turn up mostly ads. How do you deal with this?

Someone posted similar questions in 2009 and 2013, but I'm guessing there may be different products now. (Also, what does it mean to "toss" vinegar in your dishwasher?)

A few years ago I bought dishwasher cleaning tablets that had stellar reviews and did nothing, so I'm feeling skeptical about all the great reviews for various products on Amazon.

I prefer the idea of using a dishwasher detergent formulated for hard water, but one review (that I can't find now) claimed that some of her dishes were destroyed by one.

So if you have a solution that you're happy with, please share. I'm renting, so whole-house solutions aren't going to cut it.

Also, any other suggestions for living with hard water? I'm worried about my glass tea kettle.

posted by FencingGal to Home & Garden (15 answers total)

I add powdered citric acid to the dishwasher detergent and it helps a lot with hard water. Rinsing agents only made things worse for me.
posted by corey flood at 10:58 AM on October 18, 2023 [5 favorites]

The white film on dishes is usually alleviated by adding dishwasher salt in the appropriate area in your dishwasher. I'd check the levels here first before you do anything else.
posted by einekleine at 11:06 AM on October 18, 2023 [3 favorites]

Like einekleine i add dishwasher salt. There is an opening in the floor of my dishwasher with a Lid that unscrews, and i pour it in there.
This may be a European Thing?
posted by 15L06 at 11:19 AM on October 18, 2023 [3 favorites]

Tossing vinegar in can mean you fill a cup or two with vinegar and run a wash cycle with just those, no soap or other dishes.

Are you using a rinse agent like Jet Dry?
Is there a filter and have you cleaned it out?



For a tea kettle, I treat with white vinegar from time to time. Soak for a bit, rinse a lot, and then heat water and dump it. Also, if you can dry out the kettle and not let drops linger, that may help.
posted by soelo at 11:26 AM on October 18, 2023 [3 favorites]

I've used this Lemi-Shine detergent booster, a citric-acid-based formula, and found it to have good results.
posted by mosst at 11:35 AM on October 18, 2023 [6 favorites]

We have very hard water, and we alleviate this by using Jet Dry as a rinse agent -- our dishwasher has a slot where we can pour some in, and it dispenses it load by load.
posted by BlahLaLa at 12:21 PM on October 18, 2023 [3 favorites]

My dishwasher repair guy advised me to put two cups of vinegar in a bowl, put the bowl in an otherwise empty dishwasher, and run it on the longest and hottest setting; repeat every two weeks. Right before I do this, I clean the trap and the plate surrounding it (removing both) and spray some vinegar in there before I put it together again. Best done right before bed because I don’t have time to wait for a long-ass dish cycle!
posted by MonkeyToes at 12:22 PM on October 18, 2023

Yeah, before trying anything else, make sure you use a rinse agent. Jet Dry and Finish are common brands in the US for this. Most dishwashers should have a reservoir for rinse agent that you'll refill after a couple dozen loads.
posted by Aleyn at 2:02 PM on October 18, 2023

We put regular generic dishwasher soap in the prewash cycle and use LemiShine in place of detergent in the main cycle.
posted by Tandem Affinity at 2:35 PM on October 18, 2023

Citric acid for the kettle. Get the cheap powder and make a solution, leave it overnight. Repeat when you see the limescale build up again. For now, you can just wait.
posted by lokta at 4:43 PM on October 18, 2023

Nthing Lemishine for the dishwasher. After years in LA with its hard water my dishes were pretty bad, and a few run-throughs with Lemishine fixed things.
posted by LadyOscar at 9:54 PM on October 18, 2023 [1 favorite]

I use a saturated citric acid solution as my rinse aid and it's done wonders in my hard water dishwasher!
posted by london explorer girl at 4:30 AM on October 19, 2023

Before we installed a whole house water filter, we used Lemi-Shine (which worked ok) until I finally bought some powdered citric acid, which was far more economical with roughly the same effect.
posted by deludingmyself at 8:14 AM on October 19, 2023

LemiShine was fantastic when we lived in a house with super hard water. I went from cloudy glasses to clear glasses, basically instantly.

I think you can now get LemiShine at Walmart. I can’t speak to their detergent, but the stuff I’m taking about I guess they are now marketing as their “booster”. I think it’s basically just citric acid.
posted by leahwrenn at 8:28 AM on October 19, 2023

For the tea kettle, I put some vinegar in once in a while to cut down on the hard water scale.
posted by leahwrenn at 8:29 AM on October 19, 2023