Unfortunately, there is no firm definition of low-flow, but it’s generally accepted that anything using 1.5 gallons per minute (gpm) or less is considered “ultra low flow,” while anything using 2.5 gallons per minute to 1.5 gallons per minute is considered “low flow.” Nowadays, thanks to standards set by the government …

What is a low flow rate?

Low flow rates deliver small amounts of vapor molecules per unit time and produce correspondingly small rates of signal change per second.

Is 1.5 gpm shower head enough?

If you’re looking for the most pressure, go for the 2.5 GPM Flow Rate, unless you are restricted because you reside in California, Colorado or New York. … That’s 40% less water output than the 2.5 GPM Flow Rate. That said, you don’t have to be mandated by a state to use a Shower Head with a 2.0 or 1.5 GPM Flow Rate.