DIY Peristaltic Pump

tungvuu · 2026-07-21T02:14:08-0400

I'm currently facing an uncontrolled surge in PO4 causing RTN/STN in some SPSs, so I've decided to use Lanthanum. I don't like dosing into 5-10 micron filters because they clog too quickly; I prefer dosing into the skimmer body. The problem is, even with significant dilution, I still need to dose continuously 24/7, with a maximum of only 100ml/day, which is less than 0.07ml/minute, and even less in the future. Diluting more is impossible because my cabinet doesn't have space for a storage container, and I'm lazy, so I prefer one diluted container to last 1-2 months or more.
Over a year ago, I followed this thread by author yury88:
https://www.reef2reef.com/threads/r...per-motor-controller-with-opensource.1042442/

and successfully built it. Although the device works well, I'm concerned about its durability over the long term because the dosing head uses a rather small, thin silicone tube. The bigger problem is that the author's firmware doesn't suit my current needs, so I've decided to modify everything.

I've been using the Kamoer FX-STP2 for over 4 years now, running continuously 24/7 (3 years for Kalkwasser and over a year for the Calcium reactor). Although the manufacturer recommends replacing the tube every 2000 hours, in reality, I've only replaced it once in over 3 years because the operating speed is quite low, only about 20-25 ml/minute. The pump is extremely quiet; only recently did the motor start making noise, and after opening it up and replacing two bearings, everything is like new again.

I'm keeping only the Nema17 motor (1.8-degree type) with MKS Servo42C driver and 12V to 5V step-down Buck converter from the old device I built according to yury88's instructions. The rest I will do:
1. Clone the pump head mechanism, clamping jaws, and machine body from the Kamoer FX-STP2 using 3D printing.
2. Added a 1.3” SSD1306 OLED screen with EC11 for quick adjustment of some basic device features.
3. Transferred control from Esp32-S3 N16R8 to MKS Servo42C driver from UART to STEP DIR.
4. Rewrote the entire software to meet specific needs, usable in many future scenarios with a modern web interface.

tungvuu · 2026-07-21T02:20:55-0400

Everything is now almost complete:
After installation, the first boot will create a WiFi SSID as ReefICU Doser. Access it using your phone (no password required), then open a browser and go to 192.168.123.2 (the OLED screen will display Access Point mode with this IP address) to access the setup interface.
I. The WEB interface consists of several tabs with different functions:
1. Settings Tab:
A. WiFi Tab: We need to go here first to configure the WiFi SSID and password. After saving, the device will automatically connect to WiFi and The AP will automatically turn off, and the OLED screen will display the Wi-Fi connection along with the new IP address assigned by the router. From now on, you can access this IP address to configure everything. With this IP address, you can also use a PC or Raspberry Pi running Tailscale to access the device from the outside network, no longer relying on the AP, which will be more convenient. Whenever your home Wi-Fi is lost or you simply change your network password, the device will automatically turn the ReefICU Doser AP back on as before.
B. The Alerts tab is for email alerts when the reservoir is low or the dosing tube needs replacing (I haven't had time to test this feature yet).
C. The OTA tab is for uploading firmware upgrades or bug fixes in the future without having to remove the Esp32 from the device to connect to a PC. The Name section allows you to change the name of the ReefICU Doser to your desired name.
D. The Calibrate tab: this is a very important section:
- Priming: used when you need to rotate the motor to prime the dosing tube, with adjustable speed and direction (clockwise or counterclockwise). The direction is also set here. This will be the direction of motor rotation in all other modes.
- Flow Calibration: Select Speed and Duration, Run pump, record the actual value, then click Add Cal Point for the device to remember the value. You can add multiple points to increase accuracy; the device will automatically calculate the average value of the points.
- Tube life: Add the time needed to change the tube and display the timer for tube usage. Note that the device only saves the time when the roller is actually rotating, not the time the device is turned on. Reset the timer after changing the tube.
2. Dose Tab: Note that the solution name and volume are used for both Manual and Schedule modes, meaning the solution name is the same, and dosing in Manual or Schedule modes will gradually deduct from the reservoir volume.
- Manual Tab: Use a single dosing cycle with customizable volume and dosing speed.
- Schedule Tab: Schedule specific dosing times.
3. 24/7 Tab: This is where I use it most often. Note that because this mode runs continuously like a Calcium or Kalkwasser furnace, only the box... Enter the name; the bottle volume is not included and is not related to the Dose tab.
- Continuous tab: the roller runs continuously at a speed of ml/minute.

- Pulse tab: used when continuous dosing is needed at a very slow speed, approximately less than 30ml/day, such as when I need to dosing Lanthanum. Due to the physical limitations of the current code, it is approximately 27ml/day. If you want smaller volumes, the motor needs to have alternating rest periods. You can set the Speed and Period; the device will calculate the roller's continuous rotation and rest times to match the desired speed.

4. Log tab: records device logs.