Aqua Pro Reverse Osmosis Filtrate Drinking Water System Refill. Now you can have the cleaner, great tasting water at your convenience, fresh from your tap. Filtrate under-sink water filtration products are easy to install, with no mess, long lasting replacement filters that can be changed with just a twist. And using filtered water from home as an alternative to bottled water. You will need an adjustable wrench and a screwdriver.