It is also useful to look into ways of collecting rainwater, which can be used for irrigation, in water recycling systems, for supplying toilets and washing machines, for filling fire tanks and other needs. Collecting and using rainwater can save you 30-50% on your water bills. Rainwater is better than tap water in some applications: for example, using rainwater in a washing machine eliminates the need to add anti-scale agents, improves wash quality and reduces the consumption of washing powders. Rainwater is best for watering plants.