Quick Answer
Consider reevaluating your tank size when water pressure drops below 30 psi or when storage capacity exceeds 1000 gallons, indicating potential over-sourcing and unnecessary energy consumption.
Assessing Water Pressure
When evaluating your tank size, consider the water pressure at the fixtures. For most households, a minimum pressure of 30 psi is recommended to ensure proper water flow. If your tank is undersized, pressure may drop below 20 psi, causing low water flow or even preventing appliances from functioning. In such cases, upgrading to a larger tank might be necessary to maintain adequate pressure.
Calculating Storage Capacity
To determine the optimal tank size, calculate your household’s water usage in gallons per day (GPD). Average usage rates are around 50 GPD for a single occupant and 150 GPD for a family of four. However, these numbers can be higher or lower depending on factors like climate, showering habits, and irrigation needs. If your storage capacity exceeds 1000 gallons, consider downsizing to reduce energy consumption and minimize the risk of water waste.
Tank Sizing Formulas and Guidelines
When selecting a tank, use the following formula to estimate the required storage capacity: (Daily water usage x Number of days of storage) / (System gallons per minute). For example, if your daily usage is 120 GPD and you want 3 days of storage, the required capacity would be: (120 GPD x 3 days) / 10 GPM = 360 gallons. Consider factors like tank material, shape, and configuration when choosing the optimal size and type for your specific needs.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.