Tablet or powder? See which type tops our test.
Don't waste your money on a dud detergent. Find out which were best for removing six common stains, including red wine and baked-on cheese.
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While tablets perform better than powders, their superior cleaning comes at a cost. The powders we’ve tested cost between 13¢ and 16¢ a wash, while tablets range from 30¢ a load up to 78¢. When you’re shopping for tablets, check how many each pack contains to make sure you’re getting value for money.
Rinse aid helps water spread evenly over the surface of your dishes, making droplets less likely to form and leave spots, and hastening drying. Almost all tablets claim to contain rinse aid. Powders often don’t have rinse aid as it needs to be released at a certain point in the wash.
Always keep your dishwasher detergent well out of reach of children, and keep the packaging so you can quickly identify the product. Medical advice is available 24/7 from the National Poisons Centre (0800 POISON). If someone ingests a detergent, call an ambulance. For more information, see our dishwasher detergent safety article.
Some products claim to be safe for septic tanks, but you should always consult your tank’s manual or manufacturer before using a new dishwasher detergent.
Buying detergent in larger packs often reduces the cost per wash. However, as they’re likely to be stored for longer, this increases the chances of moisture in the air causing tablets stick together and powder to clump.
To help avoid this, keep your detergent in an airtight container, unless the manufacturer’s packaging can be sealed completely. Keep the original packaging, as this can help with identification if someone ingests it or the product’s recalled.
Phosphates are bad for the environment. They promote algal growth in waterways, which chokes the natural vegetation. Until recently, it was common for phosphates to be used in household detergents as they help remove food and grease and soften water.
Phosphates are no longer necessary in dishwasher detergents, and none of our latest test batch contain them, according to their manufacturers. Instead they rely on enzymes and surfactants. Our testing shows this doesn’t affect their ability to clean, as the top-performing products for the past two years were all phosphate-free.
However, phosphates may still be in some detergents. Parallel-imported detergents, even when sold under the same name, might have a different formula and performance to those sold in supermarkets. Over the next few years it will become unnecessary to make phosphate-free claims, as it becomes accepted that dishwasher detergents shouldn’t contain them.
For this year’s test we included three parallel imported dishwasher detergents. We don’t normally test these types of products as confirming their ongoing availability is difficult. This proved the case with two of these detergents – we couldn’t find them in stores by time of publication (so we haven’t published their test results).
Parallel imported detergents are genuine (in other words, non-counterfeit) products brought into the country by a store or distributor without the manufacturer’s permission. For example, Reckitt Benckiser New Zealand owns the Finish brand and supplies most stores, such as supermarkets, with formulas and approved claims it considers relevant for the New Zealand market. However, some companies, such as The Warehouse, import Finish products from other regions in the world. These imported products may not comply with local regulatory requirements.
Parallel imported products can often be identified by languages other than English on the packaging, and a safety and ingredients sticker added with information, such as the importer name and National Poisons Centre information.
Often a parallel imported product will have an almost identical name to ones provided by the local distributor, but they likely have different formulations meaning they’ll perform differently.
While we couldn’t publish the results for two of the parallel imported products, testing them did help us answer a few questions.
Of the three parallel imported products, the two that are no longer available would have earnt our recommendation. The one that’s still available, Finish Powerball Quantum sold at The Warehouse, didn’t quite meet this threshold as it was poor at removing red wine residue.
Since 2007, dishwasher detergents sold here can’t have a pH above 12.5. With every dishwasher detergent test, we check if any breach this threshold. All three parallel imported products had a pH below 12.5.
We found a few parallel imported Finish detergents that looked very similar to New Zealand licensed products. However, Reckitt Benckiser New Zealand, which produces Finish, told us that the formulas of parallel imported products will likely be different to those it supplies and are sold in supermarkets.