We work with you to find the perfect sized Pioneer rainwater tank to fit your needs. Generally, multiplying your roof size by ten will estimate the minimum water storage you should have. For example, a 3000 square foot roof might use a Pioneer XL23 (30,000 gallons). In addition to your roof size, we also take into account how many people the water will be serving, and how you plan to use your rainwater. For many, a rainwater system may only be used for potable drinking water, while others may use their rainwater for watering gardens, filling pools, and hydrating livestock. Making sure you have the right size tank means less water wasted.