The short answer: different spraying pressures produce different spray patterns and results.
Most people tend to pump their sprayer to the maximum pressure, assuming it's the most efficient approach. The common belief is - the more air in the tank, the longer the spray time before the need to re-pressurise. And since many sprayers lack a pressure gauge, users typically pump until they physically can't anymore.
But maxing out the pressure isn’t always the best idea.
If you're using a sprayer with a built-in pressure gauge, like our MAX 2 or RS backpack sprayers, you can monitor and adjust the internal pressure easily. If your sprayer doesn’t have a gauge, you can still manage pressure effectively by either:
Using a constant pressure valve, which limits output to a set pressure.
Or simply being mindful of how much you pump, varying the pressure you put into the tank.
For many general applications, just a few pumps is enough to reach 1 bar of pressure - often the ideal setting for a wide range of garden and horticultural uses.
Let’s break it down. When you pressurise your tank, air pushes the liquid out through the nozzle. The higher the pressure, the faster and finer the spray.
That sounds good - until it’s not.
Higher pressure = finer mist, which means more drift and potential waste, especially outdoors.
Fine mist can require repeat application to ensure proper coverage.
Larger droplets, which come from lower pressure, tend to land more effectively and stay where they’re sprayed.
For most garden applications, like applying weed killers, moss treatments, or plant protection products, a pressure between 1.0 and 1.5 bar gives better coverage, less waste, and more efficient use of the product.
Another benefit? Lower pressure requires less effort. Just a few strokes of the compression handle and you’re good to go for several minutes.
While applying moss killer with our MAX 2 sprayer, we only needed to reach about 1 bar even when using a 2.5-metre telescopic lance. It took around 10 pumps to pressurise the tank initially, giving us a steady spray for over 3.5 minutes. A quick 4-pump top-up, and we were ready to continue. No hard work. No wasted product. A perfect spray pattern.
Yes, you can use telescopic lances at lower pressures. Here’s how to estimate the pressure needed:
It takes approximately 0.1 bar to lift liquid 1 metre. So, if using a 5.4-metre lance vertically with the tank on the ground (plus your own height), you might need up to 2 bar to maintain effective spray at the nozzle.
But realistically, lances aren’t held perfectly vertical, and most people carry their sprayers on their shoulder, reducing the lift distance and pressure needed.
There are only a few scenarios where higher pressure is recommended:
When using long spray lances.
When applying thicker (higher viscosity) liquids that require more force to pass through the nozzle.
Always check the product’s application instructions - some may specify a minimum pressure for best results. And in those cases, you may also need a larger nozzle, which is a topic we’ll cover in a future blog.
If your tank seems to run out of pressure too quickly, it might not be the tank, it could be too much pressure. Reducing it will likely save effort, save product, and give you better results.
Smarter spraying starts with the right pressure.