Tommee Tippee Perfect Prep machine is designed for use with water straight from the tap so there is no need to pre-boil the water using a kettle or use bottled water. The Tommee Tippee Perfect Prep filters feature a unique filtration membrane which removes bacteria and other contaminates that can be found in water. This ensures that Tommee Tippee water is clean and safe to make a bottle feed. Do these filters fit both the original and Day & Night Tommee Tippee Perfect Prep machines? The Tommee Tippee plain white filter and blue/ white filters are compatible with both Perfect Prep Machines. Can I use other branded filters in my Tommee Tippee Perfect Prep machine? Tommee Tippee only recommend you use Tommee Tippee Perfect Prep Replacement Filters in the Perfect Prep machine. The filter may look a lot like other water filters but inside is a unique filtration membrane designed to remove impurities and contaminants. Most standard water filters do not include an anti-bacterial filtration membrane so will NOT remove bacteria. It is therefore extremely important to ensure that you are buying and using the correct Tommee Tippee anti-bacterial filter. How long will each filter last? On average each Perfect Prep filter should last around 3 months, this depends on the frequency of use and what size bottles you are preparing. The original Perfect Prep machine features a warning light which will indicate when the filter is due to be replaced and the Day & Night version will display a message on the screen. What are the black particles I can see on the packaging or on the filter? Small particles of carbon may be in the bag or on the surface of Tommee Tippee filter. These dust particles are harmless and will be reduced during the initial set up process when submerging in clean fresh water. Do Tommee Tippee Perfect Prep filters have a use-by date? Tommee Tippee filters do not have a use-by date however they have been certified to food grade and are sterilised so they should remain unopened until you are ready to use them.