Dishwasher tablets are practical. You don't have to fiddle with dishwasher detergent powder or liquid, but can simply place a tablet into the detergent dispenser compartment.
If your region has very hard water, you should add water softener salt to prevent limescale build-up. Oh - and don't forget a rinse aid.
But how do tablets match up in terms of environmental sustainability? And what should eco-conscious consumers be mindful of when using them?
First of all, there's the plastic to consider. Most dishwasher tablets are sold in packaged form - unpackaged tablets are rare.
"The packaging film is usually made of polyvinyl alcohol. While an added burden on waste water treatment plants, it's biodegradable, according to the German Environment Agency," says chemist Kerstin Effers.
Detergent powder, by contrast, isn't packaged in plastic.
Another consideration: Not all tablets are created equal. Classic tablets contain detergent only, while 3-in-1 tablets combine detergent, dishwasher salt and rinse aid, Effers notes.
If you use detergent powder and want to use dishwasher salt and rinse aid as well, you have to add them separately. "This has the advantage of allowing you to gear the amounts to the water hardness and degree of soiling," she says.
Added separately, the three components "can fulfil their respective functions in the dishwasher at the right moments, and thereby be maximally effective." So long as you use the right amount of detergent, that is.
When it comes to washing away burnt-on food on pots or pans, for example, you'll need a full dose of detergent, compared with a minimum dose for lightly soiled items in a quick wash cycle, advises the German consumer watchdog Stiftung Warentest.
Here's a tip: After you've measured the required amount, mark the spot on the scoop that comes with the detergent package. This will make it easier the next time you wash dishes.
If you properly measure the amounts of detergent, dishwasher salt and rinse aid for every wash cycle, you won't use more of them than needed, as can happen with 3-in-1 tablets. So if you get the doses right, in the long run it's more sustainable for the environment - and for your wallet too.
Speaking of dishwasher tablets, they were long criticized because many of them contained benzotriazole, a synthetic chemical used primarily as a corrosion inhibitor. It's suspected of disrupting the normal functioning of hormones and resists biodegradation.
The good news, says chemist Effers, is that dishwasher detergent manufacturers now do without benzotriazole. "On the basis of their components, all of the products in our most recent test got a positive environmental assessment in regard to water pollution," reports the project leader at Stiftung Warentest.
What if you don't want to use either tablets or commercial detergent powder? While the internet has no shortage of instructions on how to make your own dishwasher powder, Effers discourages DIY formulas.
"Some of them are simply nonsensical," she says, "combining, for instance, washing soda and citric acid. You then get a tablet that fizzes nicely, but the two components neutralize each other and have no effect."
Using substitute substances isn't without risk. "Some people replace rinse aid with vinegar. The question is whether the machine and its gaskets can tolerate it undamaged," Effers warns. "To be on the safe side, you should ask the machine's manufacturer."
Breaking a dishwasher by using unsuitable cleaning agents isn't exactly in the interests of environmental sustainability.
Effers has another tip instead: "If you prefer a more environmentally friendly dishwasher detergent, you can look for a seal of approval," certifying that the product is sustainable.