Peristaltic pumps troubleshooting

Hi all,
I am setting the dosing system to regulate pH and nutrients in the water.
The peristaltic pumps I have are 3V (for the motor) and are supposed to have a flow rate of 5ml/mn - see details here. I ordered them because I thought I could plug them on the 3V3 VCC pin of the Raspberry Pi.
Now that I have connected the pumps, I am realizing that they are simply not pumping anything.
This might be caused by:

  • Wrong tubing - perhaps the tubes are not exactly the right dimensions and pressure is lost

  • Pump not powerful enough - need to change the pump

  • Not enough current from the Pi - need to plug the pump to an external source

Has anyone got experience with this kind of issue? What’s the most likely cause? It’s not easy getting tubing or pumps where I am - they are imported from China - so I wanted to get some advice before I go ahead.

Thanks !

The Pi’s 3V3 is really not meant for doing anything other than driving logic level items. It’s not a good idea.

Get a stepdown driver so you can supply enough current to the pumps.

I have experienced myself exactly the same problem with a 12V peristaltic pump. Several reasons:

  1. Your pump is 5W which lead a current of 1.5A. You are lucky if your Pi has not burned its outputs. Usually in automation, we use 24V devices to have low currents for the same power. You need an external power supply, don’t use the Pi power lines.

  2. 5W is a small power, your pump won’t be able to ascend a lot, so I recommend to have the pump a bit lower than the suction point, and of course the output lower than both of them.

  3. Fertilisers are not as fluid as water. You have to compensate when you choose the flow rate. Your pump is probably undersized.


Thanks both. I got at 12V / 1A external power supply and 12V pumps, and they work great.