Step-by-step
Step 1: Decide build vs buyHonest reality: Eheim Twin + Petlibro are $25-40 retail. Building a DIY feeder from scratch costs $20-40 in parts + 4-8 hours of work. Most aquarists are better off buying.
Step 2: Build only if you want a programming projectDIY feeder makes sense if: you want a programmable feeder with custom feeding schedules, you have an Arduino + servos lying around, you want to integrate with home automation (Home Assistant, Apex).
Step 3: Mount servo + feeder cupServo motor rotates a sliding door on the feeder cup. Mount the assembly above the tank with a bracket.
Step 4: Wire Arduino + servoServo: signal pin to Arduino digital pin 9. Servo: power to 5V battery. Servo: ground to Arduino ground. Battery to Arduino VIN.
Step 5: Program feeding scheduleUse Arduino IDE: setup() initializes servo. loop() checks RTC time; if feeding time, rotate servo to dispense, wait 2 seconds, rotate back. Feed 2-3x daily.
Step 6: Test and tuneTest dispense over a paper plate first. Verify portion size. Adjust servo angle or rotation duration to control food amount.
Step 7: Mount above tankPosition feeder above tank + bracket secures to stand or wall. Make sure servo + Arduino are protected from humidity (project enclosure).
FAQ
Should I build or buy an auto-feeder?
95% of aquarists should buy. Eheim Twin + Petlibro are $25-40 with proven reliability. DIY only makes sense for programming hobbyists or home-automation integration.
Are auto-feeders accurate?
Reliable brands (Eheim, Petlibro) dose consistent portions. Cheap brands ($10) have variable dispensing + jams = ammonia spike risk.
Can auto-feeders replace a person while on vacation?
For 7-14 day trips: yes. For longer: combine auto-feeder with neighbor check-ins for power + leak alerts.