Automatic Fish Feeder





Introduction: Automatic Fish Feeder

When you are in your home and no one to care for your fish, you can rely on homemade fish feeder. The production takes approximately 3 hours, about 2 hours for the mechanical part and 1 hour for the electronics. Also you will not overfeed your fish or leave them hungry. Suitable for people with busy schedules or people on vacation.

Step 1: What You'll Need

Мechanical parts:

  • box
  • caliper
  • sandpaper
  • permanent marker
  • DC motor
  • wheel
  • nut
  • rubber
  • soldering iron
  • dremel
  • hot silicone gun
  • cutting disc
  • spring

Electrical parts:

  • 555 timer
  • 5V relay
  • 2x 47Kohm resistors
  • 10Kohm potentiometer
  • 10uF electrolytic capacitor
  • 10uF electrolytic capacitor OR micro button
  • 1000uF electrolytic capacitor
  • 0.1uF ceramic capacitor

Step 2: Marking and Cutting

Mark and cut the pipe, the pin and the box size and appropriate tool if you do not have a dremel you can use manual hacksaw.

Step 3: Installing the Parts in the Box

Placing the stud in wheel, fix with pin and conect the spring with stud.

Step 4: Connect the Parts

Before connecting filing the holes of the tubes. After that conect the tubes with hot siliconе gun, also DC motor to box.

Step 5: Electical Part

Buy a relay timer or make the scheme.

Step 6: All Parts in the Box

Put all parts in the box and connect wheel to the motor by elastic and close the box.

Step 7: Finish and Test

  1. Set the timer.
  2. Connect the transformator and timer to contact.
  3. Connect the transformer to the fish feeder with conductors.
  4. Fill the feeder with food.

  5. Now you can go out camping and don't worry about your fish!


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    Please be positive and constructive.





    Nice Instructable! I have turtles and I would like an automatic feeder for them, but I'm afraid they might knock it over or splash water into it, soaking the food and jamming the food dispension.
    So far I haven't seen many designs that are decently splash proof. do you have suggestions?


    8 replies

    Hooking it over the edge of your tank might work.

    Bend a couple of metal strips like this (not to scale): _

    | |___|

    The first, small, upside-down 'U' hooks over the tank. The second, wider 'U' holds the feeder box (maybe screw it in place for stability). You'll need 2 strips for balance, you'll have to be careful of the position(s) of the motor and pulley and you may need/want to experiment with the hopper's and tube's positioning to keep the food outside the tank for as long as possible.

    Sorry, the 'image' came out wrong - hopefully this'll work better..:


    | |___|

    Тhe problem may be solved if you use a larger pipe and put the unit on a stand (higher). Can you send me a picture of your aquarium?

    Sure! I haven't built any official automatic feeder. There have been a few prototypes but never a final.
    The tank is probably too small for them :P


    I also think that the tank is too small for them. Feeder that you need something like this it?

    I've seen that before :P

    The reason I didn't like it was that the top opening is exposed, each feed amount is not consistent, and it could easily be knocked over by my silly turtles.

    I haven't seen underwater feeders yet... That would be cool.

    I thikl that will best do stand feeder to which it can not reach your turtles. everything else will be expensive and not rational.

    I have an idea how the feeder is under water and the food is dry to the launch. This is the scheme.

    It is not impossible, just difficult for realization.


    Underwater feeder. Great idea to look into.

    I'm thinking about maybe a two stage door, like in spaceships. There can be an intermediate room.


    This looks interesting, but I'm not really sure how it works. Maybe you could add some additional info about how this attaches to the fish tank, functions, etc.

    That would be very helpful. Just a tip! :)

    2 replies

    I hope this helps you understand how it works. :)


    Thanks for comment :) I'll make some updates and will share video.