HydroHexRead the push.
The round gauge at the barrel measures how hard water pushes at the splitter, in pounds per square inch (psi). Water can press against a closed valve even while flow through it is zero.
LESSON 2 OF 3
Pressure system
The pump sends water up one pipe. At the top, a set of valves sends it back down to the plants. Follow the route and try cutting off just one sprayer.
FLOOR 5 / MIST
Turn the valve
THE TOP OF THE TOWER
Find the right knob
The top chamber supplies 15 knobs. Each one is engraved with a floor, a job, and its outlet numbers. Floor 1 sits just above the barrel.
| Knob | What it feeds | Outlets |
|---|---|---|
| DRIP | Front of each plant cup | 19–23 |
| AUX | Green ring sprayers | 42–46 |
| MIST | Three sprayers in the ceiling | 51–53 |
How do I read the gauge and the meter?
Read the amount moving.
The meter sits before the water divides. Flow is the volume passing it per minute. For example, if 1.0 liter per minute passes the meter and 0.3 returns through the bypass, 0.7 goes up the tower. This example assumes steady flow, a closed drain, and no leaks.
Check at the sprayer.
Water uses pressure to climb the tower and to pass through narrow tubes and valves. To find pressure at a working sprayer, measure just before its tip while it sprays. The animation shows the routes. Measuring the printed tower will tell us its pressure and spray quality.
What makes the pump stop?
The pump’s own switch can stop the motor when pressure builds at its outlet, then restart it as pressure falls. Closing one floor valve can leave many other paths open. Opening the barrel bypass gives water another place to go.
Pentair lists 100 psi as the switch setting for the Shurflo 8000-783-238 and 1.6 gallons per minute at open flow. Those are different operating conditions. The printed head’s working pressure has yet to be measured. Pentair pump specifications ↗