More than half of us have a dishwasher in our homes, and while the magic box that does the washing up is doing most of the hard work, what you put in it matters too.
The dishwasher detergent you choose will contribute a significant portion of the running costs over the life of your dishwasher, but dishwashers are generally more efficient than hand washing, so using one will still save you money. Buying larger packs of dishwasher detergent will usually reduce your cost per wash, even if you only run your dishwasher occasionally. But keep in mind that most detergents have a recommended shelf life of two years.
There are two main types of dishwasher detergents – tablets and powders. There are also gels, which look more like a liquid detergent; however they're quite new to the market.
Take a tablet
Tablets are convenient (especially with dissolvable wrappers), generally perform better than powders and often include rinse aid, but they're generally more expensive per wash than their powder counterparts. Even so, they're the most popular detergent type, making up over two-thirds of dishwasher detergent sales.
Powders generally cost less than tablets, but tend not to perform as well. Most packs state a recommended dosage regardless of the dishwasher, while some have recommended dosage based on the dishwasher you use, so the amount you're using per wash can vary. Erring towards larger dosages will tend to give you slightly better results, but you'll use more detergent, pushing up your cost per wash.
While you may think your dishwasher is clean – after all, it spends all its time cleaning! – grease and limescale tend to build up in hard-to-see parts like the filters, spray arms, pipes, water pump and drains. Using a dishwasher cleaner every now and then may help to keep all these important parts clean. However, you could also do it without buying yet another product – check out our article on how to clean your dishwasher.
Rinse aid works in the rinse cycle to thoroughly clear away detergent and food residues. It aids in drying performance and helps minimise water spotting by reducing surface tension in water droplets so they'll sheet off your plates and glasses more easily. It also helps to prevent the glaze on crockery being stripped away and glassware looking cloudy and scratched, which happens over time due to the high pH level in detergents – basically, rinse aid is supposed to keep your glassware and crockery shiny. Keep the rinse aid dispenser in your dishwasher topped up for best performance. This is especially important if you use a powder detergent – most tablet detergents have rinse aid built in.
Dirty dishes waiting to be cleaned in the dishwasher can contribute to a smell building up between washes, to the point where you start getting a nasty whiff when you open and close the door. A freshener helps to combat that, but many people swear by this natural approach: try popping a squeezed-out half a lemon in the cutlery basket before running the dishwasher.
Yes. Phosphates have traditionally been used in dishwasher detergents but contribute to algal blooms and are bad news for the environment. The good news is that phosphate-free dishwashing detergents can perform as well or better than their phosphate-containing counterparts (the best performers in our test are all phosphate-free) for the same or even lower price. So go phosphate-free and you'll get good washing performance, while reducing your impact on the environment.
On the subject of phosphates, you may also notice some hand dishwashing liquids also claim to be phosphate free. While this sounds good on the surface, you can safely ignore this claim, or the lack of one, as no dishwashing liquids sold in Australia contain phosphates anyway. So it's kind of the equivalent of a detergent claiming it's 'sugar free' – it may well be true, but it's not exactly a key benefit.
Dishwashing detergent is alkaline and can be extremely dangerous if swallowed, causing a corrosive reaction in the mouth and throat. Tablets and gels sometimes look and smell like candy and can grab the attention of kids, so it's extremely important to keep them well out of reach of little fingers. Don't rely on supposedly child-resistant caps or packaging.