citric acid for cleaning

On one of the recent podcast episodes there was mention of citric acid for cleaning, but not much how-to detail. And a search here didn't bring back anything comprehensive. It will be helpful for me (since I have some on hand for kitchen use), and hopefully others if we can capture some info here about the use of citric acid for cleaning.

1. What are the best uses for citric acid, especially
 a. As a replacement for toxic cleaner
 b. As compared to other safe cleaners
2. Usages in solution?
 a. What concentration?
3. Usages directly in crystal/powder form?
4. What have you tried it for that didn't work?
5. Did it ever ruin/damage anything you tried it on?

I use Lemi Shine. It's mostly citric acid, as I understand. It also claims "natural citrus oils" are in it. Non-toxic, biodegradable, phosphate free, no fillers or dyes. It's available in stores by the dishwasher detergent. The best use I have found for it is cleaning intricate brass parts. The concentration is not too important, I just mix some in warm water and soak the brass until it looks shiny, then rub it with a rag. It's never damaged anything for me.

Before dumping washing water that used citric acid into a greywater system, would it be wise to neutralize the washing water with washing soda (sodium carbonate) or sifted hardwood ash? I'm uncertain what effect the washings would have on the surrounding soil.

Trying to make the studio more environmentally friendly I use citric acid as a pickle for cleaning pieces after I  silver solder them. Depending on what I'm cleaning in my ultrasonic cleaner it works fantastic for removing oils and grease. Polishing in my tumbler a dash of Lemi Shine cleans items very nicely.

It does an amazing job of cleaning toilets throw some in the water and leave it for hours and the limescale deposits just flake off. It makes it so clean it looks brand new again. I honestly wasn't expecting it to work so well so didn't keep track of quantity used. I am sure its good for descaling the kettle too.

Citric acid (and other acidic cleaners) are really good at getting rid of mineral-based messes. The stronger the acid, the stronger the cleaning power (and the lower and more dangerous the PH), Calcium deposits, hard water deposits, are best taken care of by acids like citric acid. Like Henry, I use mine mostly in my toilets, and it works wonders!

Hi,

I tried mixing my own 5% citric acid by dissolving store bought powder in water. When used on surfaces, it leaves a white film. Any idea what this is and if there something I can add to the solution so it doesn't leave a film?

Thanks in advance!