I have been looking for a rainwater collection facility to harvest rainwater to flush my toilet and then I came upon this website. It seemed to good to be true but I went ahead and made a purchase of the system and a water butt. It was a chalenging install as there was not a loty of room to install this in my bathroom but the system is easily configurable and the right holes could be drilled in the right places to make this work. The system works seamlessly. It fills with water when it rains and tops up from the mains when it gets too low. As it works by gravity, it is slow filling up the tank. 3 mins for a short flush and 5 mins for a long flush but this does not cause any issues. All in all, I am extrtemely happy with the product and would recommend it to anyone looking to reduce their footprint on the planet.