The only DIY dishwasher powder that works: 15 g percarbonate, less than $0.15 per load.
It is well known that the major washing powder ingredient in many cleaning products is washing soda, sodium carbonate. The problem is, no matter how much you use, your dishes will be very clean, but there will be a nano film of white deposit visible on glass and metals.
Because the deposit is from hard water, therefore many DIY dishwasher powders work if you have soft water. At least acceptable. It wouldn't work at all if you have very hard water over 400 ppm, borderline drinkable water. But that's what a lot of households have in America.
To recap, all you need to remove the white film is to use about 10 g of citric acid crystals in the final rinse for the whole load, getting you crystal clear glasses.
The problem is how to apply that citric acid. It must be applied after the alkaline washing powder is rinsed away, or both the washing and the rinsing functions will be neutralized. Cleaning needs a high pH to work. The rinsing needs a low pH. The crystals should be applied before the hot rinse finishes and the dry cycle starts. You can even use cold water rinsing for a few minutes. But then you need to dry all over again.
I was thinking of starting a company to sell a gadget to time the release of crystals inside the dishwasher. I tried an automatic fish feeder and it sure works. You have more than an hour of a window to release the crystals. But it's messy with the food. It has to be custom-made.
I have been wondering how difficult is the problem. I looked at the ingredients of the dishwasher powder of 7th generation. I don't think the citrus in there works. It's the enzymes. So I didn't think we can find some common chemical to add to the powder to remove the white film.
But I was wrong. Percarbonate does it. It is washing soda plus hydrogen peroxide. So you can experiment with those two ingredients. Maybe you can add 50 cc of 3% peroxide into the washer after the initial drain of leftover water. I don't need to try that. I always have percarbonate because it's another universal ingredient. It's basically oxiclean without fillers and other stuff, pure.
Also, a dishwasher load is about 30 g. So you can add another 15 g of washing soda.
Unfortunately, the formula doesn't save you money. The 7th generation powder is about as cheap as pure washing soda from Walmart. The percarbonate is several times more expensive from Amazon. But then dishwasher powders aren't that good in general. That's why you have all sorts of fancy liquid detergents and pods. My formula is cheaper than those and probably better, depending on how much percarbonate you add.
I also use 20% to 30% citric acid crystal solution by weight as a rinse aid. That is for 100 ml of water, it weighs about 100 g. I dissolve 30 g of crystal in it. But no matter how you increase the dose of the dishwasher, it's never enough to achieve 10 g per load. And the refill of the rinse aid is very inconvenient.
But the washing machine is lovely. There is a fabric conditioner cycle for you to add anything. I learn from the dishwasher. My laundry formula is just washing soda for the main washer with optional percarbonate. And 30% citric acid as the fabric conditioner. So there should be no calcium build-up in the fabrics. So it's indeed a fabric conditioner.
