Pressure Tank Sizing for Small Farms in the Central Valley — Why Most Are Too Small
We spend a lot of time out in the flat-farm geography of western Tulare County and Kings County, from Hanford out toward Lemoore and Corcoran. We see a common theme in the irrigation setups on these small farms: everyone is dealing with constant pump failures. When we get out there, the culprit is almost always the same: “Why does my pressure tank keep failing or my pump run constantly during irrigation?” The answer is that their pressure tank is simply too small for the job.
Why Residential Specs Don’t Work on Farms
The mistake happens when someone treats a small farm like a normal house. A standard residential pressure tank is designed for a home—a shower, a washing machine, and a kitchen sink. But on a small farm, you aren’t just running a kitchen sink. You might have drip lines running for your trees, a livestock waterer filling up, and a wash-down hose in the barn—all at the same time.
If your tank is sized for a house, it cannot handle the volume of water needed for these multiple draw points. Every time you turn on a drip line, the pump has to kick on. Turn on the livestock waterer, and the pump is forced to run even longer. An undersized tank forces the pump to cycle on and off every time a new draw point opens, or worse, forces the pump to run constantly to try to keep up with the total demand.
The Real Cost of Undersizing
The real cost of an undersized tank isn’t just the price of the tank itself—it’s the cost of burning out a pump motor that should have lasted another five years. Constant, rapid cycling burns up motor windings, and running a pump at continuous high-load for irrigation when it wasn’t designed for it will cause the bearings to fail. We see it all the time: a $500 tank could have saved a $4,000 pump repair.
Calculating the Right Size
To get the right size, you need to calculate the “drawdown” requirement based on your maximum potential usage scenario. We look at the flow rate (gallons per minute) of all your equipment running simultaneously, and we size the tank to provide enough cushion so that the pump only kicks on when it absolutely needs to, and runs for a sufficient, healthy amount of time once it does. It’s about balancing the pump’s capacity with the storage capacity of the tank to ensure the entire system has a long, stable life.
Ingram Pump serves small farm operations across Kings and Tulare County — from Hanford to Pixley. We’ll size it right the first time.
Frequently Asked Questions
Why is my pressure tank failing frequently?
Pressure tanks on small farms in Hanford or Lemoore often fail because they were sized for residential, not agricultural, demands. When you have multiple simultaneous draw points like drip lines and livestock, an undersized tank constantly cycles, leading to premature bladder failure.
How do I calculate the right tank size?
You must calculate your maximum potential simultaneous water usage based on all equipment running together. We then size the tank to provide enough drawdown cushion so the pump runs for a healthy, sustained period, rather than turning on for just a few seconds at a time.
What are the risks of an undersized tank?
The risks are significant and expensive: it forces your pump to cycle rapidly, which burns out motor windings, and causes excessive wear on mechanical parts. In the long run, investing in the right size tank now saves thousands in premature pump replacements.